I had a p0420 on my 09 versa, I replaced the converter with a cheap aftermarket one, it not only did not fix the issue, it made the exhaust fumes smell super awful which then protruded into the cabin. I had to bite the bullet and buy a genuine nissan oem part, however it fixed the issue and no more raw exhast fumes smell in my car! drives like brand new now! so get a OEM one dont cheap out and learn the hard way!
Thanks, Eric! I'm glad you're still around. This was a great overview. All these checks are simple enough to do in my driveway before I drop $500 on a new cat.
I had a P0420 code on my recently purchased car, despite it having a brand new catalytic converter. I replaced the O2 sensors (since the cat was new) but the code remained. In the end I found that the spark plugs were bad and had killed the new converter by dumping unburnt fuel into it. After replacing the cat again, the code disappeared. So yeah, trust the OBD readings imho :)
Good to see you Eric back in the shop. I'll tell you, his last video in the shop kinda got me a little choked up. Eric, you will forever be my sensei of Automotive Mechanics.
I had one instance where the P0420 code came on the heels of other random O2 sensor codes. The sensor was replaced and it has been fine for 50K miles. The history matters most. I agree it mostly points to a bad cat, especially with restriction symptoms. It can't work without flow.
You're supposed to check exhaust back pressure to diag a restricted exhaust. This test is 100 percent accurate unlike the attempt to diag by engine vacuum. It doesnt matter what temp the cat is if its plugged. Temp doesn't diag restricted exhaust either. Just more wasted time. Test back pressure by removing an o2 sensor and installing a pressure gauge. Accurate and quick. Less than 5 minutes to properly diag. You have more than 5 minutes into 3 different incorrect attempts to diag. Flat rate techs do not have time to waste on improper techniques.
We have this code caused by broken exhaust manifold bolts... causing exhaust leak. Causing the sensors the think it was running lean. Fuel trims were way high. Was dumping fuel unnecessarily.... causing fouled plugs and high readings at the cat. Ripped out the exhaust. Welded nuts on the broken bolts. Removed those. Waiting on new headers and catback
I really love and appreciate Eric's videos. The car in this video obviously had problems and needed a CAT. Regarding the P0420 code, I've had a different experience that may help others. My 2010 Subaru Forester, 159K miles, ran great, no codes other than P0420. I researched for days and scanned the O2 sensors similar to what Eric and other channels describe and checked for exhaust leaks. I could not make much of the changing O2 sensor voltages and figured they must be good because they did not trigger any codes. My scanner's (Innova 3040rs) live data function also displays CAT internal temperature (1600F), so I thought it was weird that the CAT was inefficient. I planned to keep the car, and I was determined to fix it. Given the lack of good aftermarket CATs for Subarus and OEM prices from $2K-$4K USD, I decided to replace both O2 sensors (actually front A/F sensor & rear O2 sensor) as a first step- since I'd be buying them anyway when replacing the CAT. Lo and behold, the CEL went off immediately! I used good OEM sensors front: Denso-2349123, Rear: Denso-2344445. Given the price of CATs, and if the car runs fine, maybe a sensor change is worth a try as long as you plan to keep the car. YMMV.
Stoked on this! Eric you're one of my og car guys on the tube. I've learned a lot from you over the years. Broke me up when you headed out of your place back when. Great to see you here.
This was extremely helpful in me learning how to properly diagnose and fix this. I have a Ford fusion with the p0420 code and I will be looking to replace my cat really soon.
Nicely Done Eric! FYI if you have a MAP sensor in your intake manifold you can use that with a scan tool as an indicator same way Eric used the pressure gauge.
I followed Eric from the beginning! Super excited he is with TRQ. That tells me that this company is high quality and worth my money. I need to buy some struts and now I know I can trust TRQ (even more).
I'm glad I watched this video. I don't have any other codes except for a p0420 and no performance issues. After changing the sensor just to be sure I'm fairly certain my catalytic converter is the issue.
Excelente explicación primera vez que escucho en español, siempre lo escucho en inglés, aunque no entiendo mucho, pero como es lenguaje automotriz hago el esfuerzo en entender. Pero mi idioma es español. Así que fue excelente escucharlos en español. Gracias. 🎉
Excellent explanation, first time I hear it in Spanish, I always hear it in English, although I don't understand much, but since it is automotive language I make the effort to understand. But my language is Spanish. So it was great to hear them in Spanish. Thank you. 🎉
I had a 2004 Taurus with the 3.0 V6. Kept getting the P0420. What I did to pass emissions was reset the code with my scanner. Then keep the scanner on and go drive the car pretty hard with a few WOTs in there too. The scanner will tell you when all the MILs are out of test mode. I would then go directly to get my emission test which is good for 2 years. The light would maybe come back on in a few days or more, but the car drove perfect with great MPGs for years.
Thanks for the step by step diagnosis. I have a 2008 Nissan Titan with 197,000 miles. Getting PO420 code. Now I know how to check with my scan tool. Thanks.
Excellent explanation, first time I hear it in Spanish, I always hear it in English, although I don't understand much, but since it is automotive language I make the effort to understand. But my language is Spanish. So it was great to hear them in Spanish. Thank you. 🎉
I needed this because I just got a replacement ecm. When I got it put on the next day I started getting the code p0420 when I have a brand new upstream and downstream sensor on my vehicle. It’s something that’s throwing the ecm off for some reason.
Thank you Eric ,that my check engine codes P0420 my 2004 toyota camry got 585,145 miles.I changed 02 sensors the code disappeared ,two days later code came back.
Had P0420 code for years on my car, would have to replace my cat before emissions to pass, had real bad oil burning. Imagine to my surprise after having poured and soaked my cylinders with Berrymans B12 for only 12 hours with the intent to fix the oil burning, as its been obvious could see the soot coming out if the tailpipe previously and would dirty the bumper it was that bad with this constant P0420 code legit actually cleared on its own maybe a day or two after just normal brief driving not even having driven on the highway in that time. After trying cat cleaners, Sea Foam, Berrymans B12 cylinder soak did the trick. It was a hard start as expected when its initially flooded but worth every penny.
Great video and very informative. My daughter in law’s car did the very same thing (174k miles). She has an Acrua TSX and I was fooled with the transmission being very low in fluid and not having an adequate OBD reader.
What should I replace first if I'm having a misfire (p0307) and a P0420? Maybe about 5-15k miles ago, I had a massive misfire causing my dash to light up showing the traction control light coming up, 4-wheel drv needing service, engine reduce power mode and engine light flashing. it only lasted for minutes and it went back to normal driving. I didn't have the money or the time to get it servied asap, but since then I've been experiencing a rough idel whenever I'm parked or stopped, less engine power, and a need to replace my sparkplugs every month (it's foulded and it smells like coolant). The one thing that I'm impressed is that it still runs well on the highway, same mpg average, and runs almost perfectly well once the sparkplugs are changed. My mechanic says I need a new engine (quoted at $10.5k for remanufactured) and highly advise that its worth it since I would be getting a 100k mile warranty with the new engine. I've been quoted less at $6k-$8k for the engine and labor, but it's still a lot of money. Since my vehicle still drives, I want to know if I should invest my money for a new engine first or look at getting a new catalytic converter in hopes to return to my normal driving experience.
if you replace the catalytic converter don't forget to get it back so you can sell it else where...or sell it right in the spot but don't forget to ask for it.❤❤❤
Very good video how to replace a cat. But I have a question to ask if its clogged why not to fill in 1.5 littres of petrol direct inside to exhaust pipe and run on cold to clean all dirt? I am saying that because saw many videos on youtube. They used petrol, adblue, foam...
Eric O(South Main Auto) has a very good test for a clogged/restricted cat which is to drill a 1/4 in hole in front and behind cat and insert a 2 inch long piece of steel brake line in each hole and then attach a vacuum/pressure gauge to each and compare pressures. When test is complete, wiggle the brake line pieces out of the holes and weld over the holes.
I have a 2009 Pontiac Vibe 2.4L at 230000 miles. I bought it used recently. No Cat codes, but I get a severe hesitation in acceleration just like you have shown in this video. I have two cats and I am thinking to replace the second one which is unmonitored by O2 sensor.
haven't seen you in a long while Eric. Welcome back! Great Video Bough myself a IR thermo reader and same issue as what you got in the video. Might be saving $$
Good video. I have the same problem (P430) but my car run well. I repair the plug of the inyector of the bank, made a tune up and verified the catalic internaly with a camara and change the upper sensor. I live in Puerto Rico. Here not due all the examination than you do only said change the catalic. The mechanic said than internal material are bad because the age. I have a camry 2004 SE 3.3 with 115,000 milles . The question is, is real than have problem internaly perhaps the car run well? Hector.
I currently have a P0171 code for System Too Lean on my 2008 Honda CR-V for the past 6 months and the troubling thing about it is that it is such a vague code that could be for a dozen different things. The vehicle has been running and driving perfectly so there are no obvious symptoms of there being anything wrong. I've had 3 shops and the Honda dealer all try to diagnose it but were unable to find the problem. I have replaced the intake tube, MAP sensor, cleaned out the throttle body, ran fuel and exhaust cleaner through the gas tank, replaced the airfuel sensor and 02 sensor and the check engine light still keeps coming back on in less than a day of me turning it off. I haven't looked into the fuel trim data but it feels like the fuel pump and fuel injectors are running fine as I have no issues with starting, idling and driving and there doesn't seem to be anything clogging the exhaust. Could it be an electrical issue that's causing the computer to think there's a problem even though there isn't?
My 2014 Jeep Grand Cherokee Laredo with the V6 throws up code P0420 but there's no symptoms tho... no drop in gas mileage and no loss of performance. The first time it disappeared was when I sprayed intake cleaner to remove carbon buildup which cleared the code at first but eventually it came back
Asking a question for understanding. I've got an 07 Dodge Grand Caravan, 3.8L V6. It runs like a scalded cat and idles very smoothly, but has the P0420 code. B1S1 (upstream) sensor is switching rapidly like it should. However the B1S2 (downstream) sensor is reading a constant and steady, very low voltage. Again, the performance is undeniable. It runs incredibly well. I don't think the Cat is clogged. With the downstream sensor only giving off a low voltage and not switching, would it be safe to say that my code may be caused by a faulty downstream sensor?
Great Information I might have a bad CAT as well. My car does not accelerate well, struggling between 30-40 MPH. Should I try the Lacquer thinner trick to clean the CAT?
My 2014 Sierra threw a p0430 code. I replaced the thermostat as I could see I wasn’t reaching full operation temperature. So far it’s running good and no more code. I’m assuming it was a fuel ratio issue.
I have an 09 kia Sedona with a V6 and both codes are up for catalyst efficiency. Car runs fine though. I do need to change the spark plugs, it's got 217k miles. I'm hoping just changing the plugs and coils will clear this up as they need done anyway.
Random question anyone know why changing the 4 tires on my 1990 Acura Integra would cause the check engine light to turn off. It has been on for 4 years and mechanic after mechanic were unable to troubleshoot. Then went to get 4 new tires and bang light is off.
Usually theres a code for the oxygen sensors so, yeah, its likely the converter or something that would harm the converter (like a leaky injector or rich condition)
+@josegonzalezr23 We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c
I have been having p0420 code for 3 months. I used catcleaner and I have 10% better fuel consuptiom. Emission test perfect. I Changed spark plugs and lambda sensor and After I changed o2 past catalyst sensor my engine light switches off and then after a week is back on, so week off/on. Today I changed the engine coolant sensor and air filter and if the light engine is back then I don't know what to do as I don't think is anything wrong with catalytic converter as the engine light would be on all the time, not week on and week off plus my car wouldn't pass emission test and fuel consumption wouldn't improve after catcleaner
+Tommy We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c
I've been driving my 09 Chevy Traverse, with the P0420 code for over a year. And it's been driving fine, maybe a little drop in gas mileage. But for some reason, the check engine light will turn on for awhile with that code. Then after driving it for a bit, the light will turn off by itself. Another thing I've been doing, is using some cat cleaner every so often. So I've been back, and forth either replacing the cat or leaving it be.
I’ve had old, misfiring spark plugs cause the P0420, P0430 codes due to incomplete fuel ignition. Check the less expensive things first. Not a car repair expert, just a shade tree mechanic on my own vehicles for 40+ years.
Sir, I have an 03 Accord V6. I have replaced all the sensors but it still jerks/bucking when accelerating at 20 miles per hour. I had a code came on P0757 shift solenoid B, replaced that and still jerks when driving 20mph I have changed the transmission fluid from Honda dealership. And still doing the jerking. I have too much sentimental value on this car. I bought it when I return from Iraq back in 2003. Please help!
Thanks for your elaborate diagnostic tips. On the other hand,my 2015 CRV,I had the cat replaced for two months,because of the code P0420,now it’s back with the same code, why ? After market cat or something else ? Thanks
+Walter Bellini We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c
√ Watch the Video
√ Buy The Part at 1A Auto 1aau.to/m/Shop-TRQ-Parts
√ Do it Yourself
√ Save Money
Ive been driving with that p0420 code for 6 years
Great move, TRQ, bringing Erick to the channel. He will bring a lot of viewers. ❤
I had a p0420 on my 09 versa, I replaced the converter with a cheap aftermarket one, it not only did not fix the issue, it made the exhaust fumes smell super awful which then protruded into the cabin. I had to bite the bullet and buy a genuine nissan oem part, however it fixed the issue and no more raw exhast fumes smell in my car! drives like brand new now! so get a OEM one dont cheap out and learn the hard way!
Very pleased to see Eric on board and creating content once again.
The only cat video on youtube that actually makes sense
Eric the Car Guy is a great teacher and very detailed in what has to be done.Keep bringing Eric back for more videos👍🏽
Thanks, Eric! I'm glad you're still around. This was a great overview. All these checks are simple enough to do in my driveway before I drop $500 on a new cat.
I’m a fan- this man knows his stuff - great advice - hard to find someone so knowledgeable and thorough-
I had a P0420 code on my recently purchased car, despite it having a brand new catalytic converter. I replaced the O2 sensors (since the cat was new) but the code remained. In the end I found that the spark plugs were bad and had killed the new converter by dumping unburnt fuel into it. After replacing the cat again, the code disappeared. So yeah, trust the OBD readings imho :)
Good to see you Eric back in the shop. I'll tell you, his last video in the shop kinda got me a little choked up. Eric, you will forever be my sensei of Automotive Mechanics.
I had one instance where the P0420 code came on the heels of other random O2 sensor codes. The sensor was replaced and it has been fine for 50K miles. The history matters most. I agree it mostly points to a bad cat, especially with restriction symptoms. It can't work without flow.
The colab I didn’t know I needed. Good to see you again Eric! Be safe, have fun, stay dirty. ❤
You're supposed to check exhaust back pressure to diag a restricted exhaust. This test is 100 percent accurate unlike the attempt to diag by engine vacuum. It doesnt matter what temp the cat is if its plugged. Temp doesn't diag restricted exhaust either. Just more wasted time. Test back pressure by removing an o2 sensor and installing a pressure gauge. Accurate and quick. Less than 5 minutes to properly diag. You have more than 5 minutes into 3 different incorrect attempts to diag. Flat rate techs do not have time to waste on improper techniques.
We have this code caused by broken exhaust manifold bolts... causing exhaust leak. Causing the sensors the think it was running lean. Fuel trims were way high. Was dumping fuel unnecessarily.... causing fouled plugs and high readings at the cat. Ripped out the exhaust. Welded nuts on the broken bolts. Removed those. Waiting on new headers and catback
Eric is a super talented car guru and his video editor is top notch too!
Thanks guys!
I really love and appreciate Eric's videos. The car in this video obviously had problems and needed a CAT. Regarding the P0420 code, I've had a different experience that may help others. My 2010 Subaru Forester, 159K miles, ran great, no codes other than P0420. I researched for days and scanned the O2 sensors similar to what Eric and other channels describe and checked for exhaust leaks. I could not make much of the changing O2 sensor voltages and figured they must be good because they did not trigger any codes. My scanner's (Innova 3040rs) live data function also displays CAT internal temperature (1600F), so I thought it was weird that the CAT was inefficient. I planned to keep the car, and I was determined to fix it. Given the lack of good aftermarket CATs for Subarus and OEM prices from $2K-$4K USD, I decided to replace both O2 sensors (actually front A/F sensor & rear O2 sensor) as a first step- since I'd be buying them anyway when replacing the CAT. Lo and behold, the CEL went off immediately! I used good OEM sensors front: Denso-2349123, Rear: Denso-2344445. Given the price of CATs, and if the car runs fine, maybe a sensor change is worth a try as long as you plan to keep the car. YMMV.
Good to see you again Eric! Thanks for putting some more quality concise videos out there. Keep'em comin'!
Stoked on this! Eric you're one of my og car guys on the tube. I've learned a lot from you over the years. Broke me up when you headed out of your place back when. Great to see you here.
This was extremely helpful in me learning how to properly diagnose and fix this. I have a Ford fusion with the p0420 code and I will be looking to replace my cat really soon.
It’s great to see and old friend again! Welcome back Eric!
Listen this I subscribed now because Erick was the first UA-cam mechanic channel I watched way back in 2013 nice to see a good mentor again
the myth! the legend!! Mr. Eric the car guy!!!!!!!!
Nice to know, my Audi cats are a couple grand each. I’m at 140k miles. Any thoughts on Cataclean or other exhaust cleaners?
Nicely Done Eric! FYI if you have a MAP sensor in your intake manifold you can use that with a scan tool as an indicator same way Eric used the pressure gauge.
Nice to see you again Eric and welcome back.
I followed Eric from the beginning! Super excited he is with TRQ. That tells me that this company is high quality and worth my money. I need to buy some struts and now I know I can trust TRQ (even more).
The causes of P0420 is broken mass air flow sensor gas cap and fuel injection system. P0420 is sometimes is error codes is number one problem.
Been following Eric for years
Could a leak in the exhaust manifold cause a PO 420 as well?
I'm glad I watched this video. I don't have any other codes except for a p0420 and no performance issues. After changing the sensor just to be sure I'm fairly certain my catalytic converter is the issue.
Excelente explicación primera vez que escucho en español, siempre lo escucho en inglés, aunque no entiendo mucho, pero como es lenguaje automotriz hago el esfuerzo en entender. Pero mi idioma es español. Así que fue excelente escucharlos en español. Gracias. 🎉
Excellent explanation, first time I hear it in Spanish, I always hear it in English, although I don't understand much, but since it is automotive language I make the effort to understand. But my language is Spanish. So it was great to hear them in Spanish. Thank you. 🎉
I had a 2004 Taurus with the 3.0 V6. Kept getting the P0420. What I did to pass emissions was reset the code with my scanner. Then keep the scanner on and go drive the car pretty hard with a few WOTs in there too. The scanner will tell you when all the MILs are out of test mode. I would then go directly to get my emission test which is good for 2 years. The light would maybe come back on in a few days or more, but the car drove perfect with great MPGs for years.
Nice addition to the TRQ videos, welcome aboard Eric!
Thank you Eric help me to diagnosis P420. Does eng oil burn for long time clogcat?
I'm a long time fan of ETCG. Glad to see him on this channel 🎉
I’ve purchased TRQ engine coils and they are wonderful and haven’t had any trouble since I purchased and installed back in march this year.
Roulette is my go-to especially after a colleague suggested trying it on Fridays got lucky last session 🍀
Thanks for the step by step diagnosis. I have a 2008 Nissan Titan with 197,000 miles. Getting PO420 code. Now I know how to check with my scan tool. Thanks.
This guy is always the best teacher
Excellent explanation, first time I hear it in Spanish, I always hear it in English, although I don't understand much, but since it is automotive language I make the effort to understand. But my language is Spanish. So it was great to hear them in Spanish. Thank you. 🎉
TRQ is a really good source for knowledge and for people wanting to see what they are getting into before starting a project
I thought it was a thorough video even though I see one person down the line here is giving you the business about improper techniques.
I needed this because I just got a replacement ecm. When I got it put on the next day I started getting the code p0420 when I have a brand new upstream and downstream sensor on my vehicle. It’s something that’s throwing the ecm off for some reason.
Get your own channel back Eric! You're too good for this!!!!!!
Thank you Eric ,that my check engine codes P0420 my 2004 toyota camry got 585,145 miles.I changed 02 sensors the code disappeared ,two days later code came back.
Had P0420 code for years on my car, would have to replace my cat before emissions to pass, had real bad oil burning. Imagine to my surprise after having poured and soaked my cylinders with Berrymans B12 for only 12 hours with the intent to fix the oil burning, as its been obvious could see the soot coming out if the tailpipe previously and would dirty the bumper it was that bad with this constant P0420 code legit actually cleared on its own maybe a day or two after just normal brief driving not even having driven on the highway in that time. After trying cat cleaners, Sea Foam, Berrymans B12 cylinder soak did the trick. It was a hard start as expected when its initially flooded but worth every penny.
Great video and very informative. My daughter in law’s car did the very same thing (174k miles). She has an Acrua TSX and I was fooled with the transmission being very low in fluid and not having an adequate OBD reader.
What should I replace first if I'm having a misfire (p0307) and a P0420?
Maybe about 5-15k miles ago, I had a massive misfire causing my dash to light up showing the traction control light coming up, 4-wheel drv needing service, engine reduce power mode and engine light flashing. it only lasted for minutes and it went back to normal driving. I didn't have the money or the time to get it servied asap, but since then I've been experiencing a rough idel whenever I'm parked or stopped, less engine power, and a need to replace my sparkplugs every month (it's foulded and it smells like coolant). The one thing that I'm impressed is that it still runs well on the highway, same mpg average, and runs almost perfectly well once the sparkplugs are changed.
My mechanic says I need a new engine (quoted at $10.5k for remanufactured) and highly advise that its worth it since I would be getting a 100k mile warranty with the new engine. I've been quoted less at $6k-$8k for the engine and labor, but it's still a lot of money.
Since my vehicle still drives, I want to know if I should invest my money for a new engine first or look at getting a new catalytic converter in hopes to return to my normal driving experience.
Nice to see Eric again!
Given the history at Eric's shop, when he said "protect your investment" I am surprised no comment was made on the topic of anti-theft measures.
All about the crash games here started on a whim now I can’t stop the excitement just builds 🚀
This has been incredibly informative! Let my troubleshooting commence...
if you replace the catalytic converter don't forget to get it back so you can sell it else where...or sell it right in the spot but don't forget to ask for it.❤❤❤
Very good video how to replace a cat.
But I have a question to ask if its clogged why not to fill in 1.5 littres of petrol direct inside to exhaust pipe and run on cold to clean all dirt?
I am saying that because saw many videos on youtube. They used petrol, adblue, foam...
Eric O(South Main Auto) has a very good test for a clogged/restricted cat which is to drill a 1/4 in hole in front and behind cat and insert a 2 inch long piece of steel brake line in each hole and then attach a vacuum/pressure gauge to each and compare pressures. When test is complete, wiggle the brake line pieces out of the holes and weld over the holes.
Love to see Eric back, Very informative.
I have a 2009 Pontiac Vibe 2.4L at 230000 miles. I bought it used recently. No Cat codes, but I get a severe hesitation in acceleration just like you have shown in this video. I have two cats and I am thinking to replace the second one which is unmonitored by O2 sensor.
haven't seen you in a long while Eric. Welcome back! Great Video Bough myself a IR thermo reader and same issue as what you got in the video. Might be saving $$
I don’t know why this code often comes up on my scanner when I have a brand new upstream and downstream sensor along with a new exhaust manifold!!!!
Good video. I have the same problem (P430) but my car run well. I repair the plug of the inyector of the bank, made a tune up and verified the catalic internaly with a camara and change the upper sensor. I live in Puerto Rico. Here not due all the examination than you do only said change the catalic. The mechanic said than internal material are bad because the age. I have a camry 2004 SE 3.3 with 115,000 milles . The question is, is real than have problem internaly perhaps the car run well? Hector.
Quick question, is it ready enough to get in there to throw in a non-fouler
I currently have a P0171 code for System Too Lean on my 2008 Honda CR-V for the past 6 months and the troubling thing about it is that it is such a vague code that could be for a dozen different things. The vehicle has been running and driving perfectly so there are no obvious symptoms of there being anything wrong. I've had 3 shops and the Honda dealer all try to diagnose it but were unable to find the problem. I have replaced the intake tube, MAP sensor, cleaned out the throttle body, ran fuel and exhaust cleaner through the gas tank, replaced the airfuel sensor and 02 sensor and the check engine light still keeps coming back on in less than a day of me turning it off. I haven't looked into the fuel trim data but it feels like the fuel pump and fuel injectors are running fine as I have no issues with starting, idling and driving and there doesn't seem to be anything clogging the exhaust. Could it be an electrical issue that's causing the computer to think there's a problem even though there isn't?
My 2014 Jeep Grand Cherokee Laredo with the V6 throws up code P0420 but there's no symptoms tho... no drop in gas mileage and no loss of performance. The first time it disappeared was when I sprayed intake cleaner to remove carbon buildup which cleared the code at first but eventually it came back
As always ETG explaining an issue well in detail, withe proper troubleshooting and repair. As a DIYer, wish I had a lift...😎
Welcome back Erick… excellent video .
Great video I have 2010 Honda pilot trq catalytic converter you think the help my I have the same problem p0430 n p0420 thanks 🙏
Asking a question for understanding. I've got an 07 Dodge Grand Caravan, 3.8L V6. It runs like a scalded cat and idles very smoothly, but has the P0420 code. B1S1 (upstream) sensor is switching rapidly like it should. However the B1S2 (downstream) sensor is reading a constant and steady, very low voltage. Again, the performance is undeniable. It runs incredibly well. I don't think the Cat is clogged.
With the downstream sensor only giving off a low voltage and not switching, would it be safe to say that my code may be caused by a faulty downstream sensor?
Will a cleaner that goes in gas tank help for few months?
Very useful video thanks, it Would be good to test catalytic converter cleaners with that kind of visual inspection.
He is good at teaching! Simply Perrfection
Great Information
I might have a bad CAT as well. My car does not accelerate well, struggling between 30-40 MPH.
Should I try the Lacquer thinner trick to clean the CAT?
If it's time to change the cat its probably time to change the 02 sensors aswell though.
Where is located the bank 1 for the Nissan Xterra 2006? Is it the left or right side?
My 2014 Sierra threw a p0430 code. I replaced the thermostat as I could see I wasn’t reaching full operation temperature. So far it’s running good and no more code. I’m assuming it was a fuel ratio issue.
In Texas, you have to pass inspection so that 420 code causes the check engine light to go on and if its on you fail..even if its driveable.
Cataclean worked fory 2020 seinna
I have an 09 kia Sedona with a V6 and both codes are up for catalyst efficiency. Car runs fine though. I do need to change the spark plugs, it's got 217k miles. I'm hoping just changing the plugs and coils will clear this up as they need done anyway.
Random question anyone know why changing the 4 tires on my 1990 Acura Integra would cause the check engine light to turn off. It has been on for 4 years and mechanic after mechanic were unable to troubleshoot. Then went to get 4 new tires and bang light is off.
I'm glad to see my man Eric again!
Dang! So cool to see Eric again!!
Well done. I get the 420 code every now and then. but I have zero engine discrepancies or signs of loss of power. just the code. Might tackle it soon.
nice job, nice demeanor in presentation
Remember, if he can do it, you can do it... thanks for watching... one of Eric favorite saying
Usually theres a code for the oxygen sensors so, yeah, its likely the converter or something that would harm the converter (like a leaky injector or rich condition)
love ya bro so happy for you ..I feel like your right where you belong lol how long have you been on board with TQR
Good to see ETCG again! I'm subbing!!!
If a car lags to turn on sometimes, could it be because of that as well?
+@josegonzalezr23 We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c
What do i do about the misfire code after changing the cat?
Cel eliminator 02 extension $8 ish a piece definitely works! Your welcome...
+John Kennedy Thanks for the feedback! 1aau.to/m/Shop-TRQ
I have been having p0420 code for 3 months. I used catcleaner and I have 10% better fuel consuptiom. Emission test perfect. I Changed spark plugs and lambda sensor and After I changed o2 past catalyst sensor my engine light switches off and then after a week is back on, so week off/on. Today I changed the engine coolant sensor and air filter and if the light engine is back then I don't know what to do as I don't think is anything wrong with catalytic converter as the engine light would be on all the time, not week on and week off plus my car wouldn't pass emission test and fuel consumption wouldn't improve after catcleaner
+Tommy We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c
I use a back pressure guage tester at the rear O2
I've been driving my 09 Chevy Traverse, with the P0420 code for over a year. And it's been driving fine, maybe a little drop in gas mileage. But for some reason, the check engine light will turn on for awhile with that code. Then after driving it for a bit, the light will turn off by itself. Another thing I've been doing, is using some cat cleaner every so often. So I've been back, and forth either replacing the cat or leaving it be.
I’ve had old, misfiring spark plugs cause the P0420, P0430 codes due to incomplete fuel ignition. Check the less expensive things first. Not a car repair expert, just a shade tree mechanic on my own vehicles for 40+ years.
Great seeing Eric here!
Oh, is it safe to say if have I to change catalytic converter to replace all O2 sensors?
Guess like asking if changing water pump to install new belt.
Sir, I have an 03 Accord V6. I have replaced all the sensors but it still jerks/bucking when accelerating at 20 miles per hour. I had a code came on P0757 shift solenoid B, replaced that and still jerks when driving 20mph I have changed the transmission fluid from Honda dealership. And still doing the jerking. I have too much sentimental value on this car. I bought it when I return from Iraq back in 2003. Please help!
1:27 what does he mean by switching ? What is supposed to switch back and forth? 😮
Thanks for your elaborate diagnostic tips. On the other hand,my 2015 CRV,I had the cat replaced for two months,because of the code P0420,now it’s back with the same code, why ? After market cat or something else ? Thanks
Thank you for the video and info
Curious question: Shouldn’t the O2 sensors have registered irregularities in it readings, because of the clogged CAT?
+Walter Bellini We wouldn't be able to diagnose an issue like that here, you may want to have a local mechanic take a look at it. Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c