My 1998 Saturn SL2 was bucking, and running rough on cold starts only. It would also stall on first crank start up, unless I pressed gas pedal down 1/3 or more, than it started fine on first start attempt. Cleaned EGR, Cleaned complete throttle body and AIC solenoid pintle, cleaned map sensor and area, new CPS, TPS, CTS, OS, FF, plugs, wires, ignition module, ignition coils, fuel pump good pressure, etc.... still same problem and 171 code running too lean. I replaced PCV and bingo! That fixed the problem!! A freaking $4 part!! Unbelievable a cheap part can cause some weird, bizarre bad start and running problems.
Thanx for this video , you made a good clear Video on this problem I had . So I know where to start and fix the problem . Very detailed well professionally made .👍
P0171 ONLY on my 2020 Ford F150. I have only 26,000 miles on it. I saw your possible reasons. I have extended warranty but my dealership doesn't do 3rd party warranties. Now what would you recommend sir? EDIT: I bought the truck brand new. This shouldn't happen so soon should it? Edit: Took it to a dealership. They replaced purge valve. But they would NOT guarantee that was the problem. I paid for diagnosis, parts and labor. If the code reappears, they told me to bring it back. And for what? Only to charge me again and possibly again and again? Thats just not right.😠
I got P0420-Catalytic converter system, bank 1 - efficiency below threshold (I’ve replaced the cat) P0276-Intake manifold air control actuator position sensor/switch - range/performance problem P0171-System too lean, bank 1 P0141-Heated oxygen sensor (HOS) 2, bank 1, heater control - circuit malfunction P0138-Heated oxygen sensor (HOS) 2, bank 1 - high voltage P0036-Heated oxygen sensor (HOS) 2, bank 1, heater control - circuit malfunction (And I’ve replace both o2 sensors on my vehicle up stream and down to be on the safe side. Only one exhaust.)
There is… your o2 sensors are your “af ratio” sensors. They’ll sometimes throw codes however they often don’t know that they’re not working. Their function can be easily checked with a cheap OBD2 scanner and seeing their response to a snap throttle test
Thank you for your good video. I have a 2017 Nissan Altima. I forgot and left the cap off after I changed my CVT fluid and drove 100 miles then the engine light went on. I put the cap back on. My scanner showed P015A, P015B, P014C, P014D code, so I changed the oxygen sensor. I cleared the codes. Then drove another 10 miles, engine light went on. Scanner showed P0171 code stored and P015A, P015B, P014C, P014D permanent. Any suggestions?
Vehicle in question is a 2003 VW Passat GLX, 6 cylinder, automatic transmission, front wheel drive. This vehicle has always had a seemingly high idle speed, even when it comes back from service at the Dealership. I am getting P0171 and P0174 for the same "too lean" condition on both right and left banks. If idle speed was set too low (on last service at an auto repair center), what do you think the chances are this might be the cause? RANDOM QUESTIONS: Does the ECM control the idle speed and the mechanic cannot adjust it? Could a low idle speed cause the ECM to calculate and inject the wrong amount of gas because the ECM is programmed to function as though the idle speed is set correctly? If the ECM knows the mix is lean, why does the ECM not adjust the mix accordingly by increasing the fuel injection interval? Could it be the idle speed has been running low . . . BECAUSE OF A VACUUM LEAK, . . . and the engine therefore has insufficient power to maintain the correct idle speed because of the weak fuel mix?
I’ve got this code on my 2006 Camry with 280k miles and I’ve noticed I also have a 16% absolute throttle position during idle when looking at the live data on my BlueDriver which I’m pretty sure is way too high. Would this most likely indicate it’s the throttle position sensor that needs replaced? The absolute throttle position percentage when the code last got tripped on the freeze frame data was 30.6%.
I had both codes right after I ran out of fuel while driving Engine was rattling on first start then goes well but the engine still stumble at 4000rpm rev
I check smoke exhaust leak, clean MAF sensor, replace pcv valve. but light still there but when my gas tank has 75% light goes off.. i could not find the problem and come back after that..
Hello everyone my car Honda civci si 2008 i have been change a lot of thing but still not working good yet it only running about 1hour after that engine started stalling. this is might be very slow leak or anything that i miss. Thank you so much for helping. P0171 code system too lean bank 1. i did change O2 sensor and MAF already. and all the boost is good.
Hi, I have had that code for over a year. It has cleared itself. Engine light goes off. Or I clear it. Last week It started running okay when cold but when hot looses power. In that year I have been driving and testing. Has new fuel pump and filter. Ideas?
It depends on what they are replacing. AND if they actually replaced the part that's causing the issue. There are so many possibilities, you might get lucky.
P0171 Code : Lean code, too much air. Air Fuel Ratio : 14.7 Air = 1 Fuel 14.7 parts of air to 1 part of fuel. 1. Vacuum Leak : 2. MAF Sensor 3. Fuel Issues : Fuel Pump, Fuel Filter, Fuel Injectors, Fuel Rail Pressure Sensor, Restricted Fuel Line 4. Exhaust Leak 5. Oxygen Sensor 6. ECM
I know nothing about pop1 code 171,I asked my neighbor and he said I need a vacuum brake booster,but he also said he didn't know if that 02 is damaged,I'm a military wife I took it to three mechanic and each one said something different with outrageous prices ,I trust my neighbor advice he said I should only get the vacuum brake booster to see if that takes care of the problem ,what do u think 🤔
![Engine Fault Code P0171 - System Too Lean Bank 1! [Symptoms, Causes, and Fixes]](http://i.ytimg.com/vi/U3JVc3VLahA/mqdefault.jpg)
![Engine Fault Code P0171 - System Too Lean Bank 1! [Symptoms, Causes, and Fixes]](/img/tr.png)
▶︎ OBD2 Scanner: amzn.to/3PHRplS
You provide so much value for free, it’s insane. Thank you man!
I appreciate you!
You can find ALL of this on the internet since like year 2000.
Great information. Thanks!! The cause on my 2004 Honda CR-V was a bad intake manifold gasket!!! Took forever to diagnosis it.
Thank you for sharing!
Same on my 2007 Element. What a rabbit hole of diagnosis, until I saw this video.
Your page giving a lot of information,thanks for your vidoes helped me a lot
My 1998 Saturn SL2 was bucking, and running rough on cold starts only. It would also stall on first crank start up, unless I pressed gas pedal down 1/3 or more, than it started fine on first start attempt. Cleaned EGR, Cleaned complete throttle body and AIC solenoid pintle, cleaned map sensor and area, new CPS, TPS, CTS, OS, FF, plugs, wires, ignition module, ignition coils, fuel pump good pressure, etc.... still same problem and 171 code running too lean. I replaced PCV and bingo! That fixed the problem!! A freaking $4 part!! Unbelievable a cheap part can cause some weird, bizarre bad start and running problems.
Thanx for this video , you made a good clear Video on this problem
I had . So I know where to start and fix the problem . Very detailed well professionally made .👍
Could it be clogged fuel injectors causing it?
Yes
what if you get this right after getting gas on a super hot day (100°) and you clear it and it doesn’t come back
My question too after 99deg today
Same here
It’s way to many things that could be wrong
That is what I thought when the video was over.
@@thelthrythquezada8397 I'm getting the code after getting gas at a sketchy place. It has gone away for right now after putting fresh gas in
Easy if it read P0171 Bank1 it means that is the Oxygen Sensor?
Perfect explanations thank you king👑👑
Is that why my van is delayed when accelerating? (Mazda Mpv 2004)
Thank you brother
and thank you!
P0171 ONLY on my 2020 Ford F150. I have only 26,000 miles on it. I saw your possible reasons. I have extended warranty but my dealership doesn't do 3rd party warranties.
Now what would you recommend sir?
EDIT:
I bought the truck brand new. This shouldn't happen so soon should it?
Edit:
Took it to a dealership. They replaced purge valve. But they would NOT guarantee that was the problem. I paid for diagnosis, parts and labor.
If the code reappears, they told me to bring it back. And for what? Only to charge me again and possibly again and again?
Thats just not right.😠
I got
P0420-Catalytic converter system, bank 1 - efficiency below threshold
(I’ve replaced the cat)
P0276-Intake manifold air control actuator position sensor/switch - range/performance problem
P0171-System too lean, bank 1
P0141-Heated oxygen sensor (HOS) 2, bank 1, heater control - circuit malfunction
P0138-Heated oxygen sensor (HOS) 2, bank 1 - high voltage
P0036-Heated oxygen sensor (HOS) 2, bank 1, heater control - circuit malfunction
(And I’ve replace both o2 sensors on my vehicle up stream and down to be on the safe side. Only one exhaust.)
My car is hesitating like it’s not getting enough air or gas
Thank you for this video! What I don't get is that if the problem is possibly in the A/F ratio sensor, then WHY is there not a code for that sensor?
Exactly i hate that lol
There is… your o2 sensors are your “af ratio” sensors. They’ll sometimes throw codes however they often don’t know that they’re not working. Their function can be easily checked with a cheap OBD2 scanner and seeing their response to a snap throttle test
Thank you for your good video. I have a 2017 Nissan Altima. I forgot and left the cap off after I changed my CVT fluid and drove 100 miles then the engine light went on. I put the cap back on. My scanner showed P015A, P015B, P014C, P014D code, so I changed the oxygen sensor. I cleared the codes. Then drove another 10 miles, engine light went on. Scanner showed P0171 code stored and P015A, P015B, P014C, P014D permanent. Any suggestions?
Vehicle in question is a 2003 VW Passat GLX, 6 cylinder, automatic transmission, front wheel drive. This vehicle has always had a seemingly high idle speed, even when it comes back from service at the Dealership.
I am getting P0171 and P0174 for the same "too lean" condition on both right and left banks. If idle speed was set too low (on last service at an auto repair center), what do you think the chances are this might be the cause?
RANDOM QUESTIONS:
Does the ECM control the idle speed and the mechanic cannot adjust it?
Could a low idle speed cause the ECM to calculate and inject the wrong amount of gas because the ECM is programmed to function as though the idle speed is set correctly?
If the ECM knows the mix is lean, why does the ECM not adjust the mix accordingly by increasing the fuel injection interval?
Could it be the idle speed has been running low . . . BECAUSE OF A VACUUM LEAK, . . . and the engine therefore has insufficient power to maintain the correct idle speed because of the weak fuel mix?
my car is ticking on warm ups but not when hot can u help with some info so i can take care of it
Could be an exhaust manifold leak. When the metal warms up it seals itself. Depends what kind of tick though if its internals related or not
I’ve got this code on my 2006 Camry with 280k miles and I’ve noticed I also have a 16% absolute throttle position during idle when looking at the live data on my BlueDriver which I’m pretty sure is way too high. Would this most likely indicate it’s the throttle position sensor that needs replaced? The absolute throttle position percentage when the code last got tripped on the freeze frame data was 30.6%.
I have a Toyota RAV4 2017 . My car had the engine light on and my painel said traction torned off .
I got the p0171 and p0174 code for my 02 GMC Seirra 1500 with a 4.8L. How can I fix those 2 codes? Or check ?
Same thing and a p0401 error code and cylinder 3 misfire
Getting a Chevy sonic for a cheap price and after scanning it I saw those popped up but contemplating if to still go ahead or save my money
I had both codes right after I ran out of fuel while driving
Engine was rattling on first start then goes well but the engine still stumble at 4000rpm rev
I check smoke exhaust leak, clean MAF sensor, replace pcv valve. but light still there but when my gas tank has 75% light goes off.. i could not find the problem and come back after that..
fuel pump
This video is utterly terrifying pray for me guys let’s hope that the new MAF I ordered fixes this bs yikes
This code has too many things to consider 😢
I've recently got this code with my 2009 lancer
Oxygen sensor . Lancer 09 i have too...
Excellent info 👏🎉
Thank you👍
Greetings from Egypt 🕊️🇪🇬🕊️
None of this repaired my vehicle .had the ec m flashed still lean. 2200 miles later non can figure it out.
Hello everyone my car Honda civci si 2008 i have been change a lot of thing but still not working good yet it only running about 1hour after that engine started stalling. this is might be very slow leak or anything that i miss. Thank you so much for helping.
P0171 code system too lean bank 1. i did change O2 sensor and MAF already. and all the boost is good.
So its the throttle body need replace
Thanks a lot.
Hi, I have had that code for over a year. It has cleared itself. Engine light goes off. Or I clear it. Last week It started running okay when cold but when hot looses power. In that year I have been driving and testing. Has new fuel pump and filter. Ideas?
Process of elimination. One expensive part then another.
Clearing the code doesn't fix the problem.
Anyone getting this code only and car randomly shuts off
Any1 with a 2011 Chevy Malibu with P0171 because i cannt find the issue
I'm getting P0316 P0171 and P0303. Does this combination rule out some of the possible problems?
How much you think that they will charge me to get it fixed
It depends on what they are replacing.
AND if they actually replaced the part that's causing the issue.
There are so many possibilities, you might get lucky.
Sup Hakeem. I have the same problem. Any updates on price? I am going threw financial hardship at the moment hopefully it doesn't cost much
You forgot to mention PCV Valve
P0171 Code : Lean code, too much air.
Air Fuel Ratio : 14.7 Air = 1 Fuel
14.7 parts of air to 1 part of fuel.
1. Vacuum Leak :
2. MAF Sensor
3. Fuel Issues : Fuel Pump, Fuel Filter, Fuel Injectors, Fuel Rail Pressure Sensor, Restricted Fuel Line
4. Exhaust Leak
5. Oxygen Sensor
6. ECM
I have a 01 Ford expedition I just want a new computer n wiring harness or just get a carburetor 302
I know nothing about pop1 code 171,I asked my neighbor and he said I need a vacuum brake booster,but he also said he didn't know if that 02 is damaged,I'm a military wife I took it to three mechanic and each one said something different with outrageous prices ,I trust my neighbor advice he said I should only get the vacuum brake booster to see if that takes care of the problem ,what do u think 🤔
If your brake booster is bad you will have inconsistent braking as well as “system too lean” I fixed my problem by replacing brake booster
I also got p0420 with the code
Oxygen sensor !
Me too,any ideas
@@davidkalger it’s the oxygen sensor
🏁🚗💨
thank you A+++++++