After installing Banks headers and full exhaust, I took my truck for another test drive this morning. SES light came on about 15 mins into drive and is telling me P0174 - Bank 2 Lean.
So that's the right/drivers side - my list of things to go check
O2 Sensor plug on that side
The MAF
The IAC
Vacuum lines ...
I am having a difficult time trying to fix my CEL issue, The vagcom scan says P0171 & P0174 Lean banks 1 and 2. I don't believe both O2's went out I have Checked and cleaned the MAF Sensor did a quick vacuum leak inspection and all seems good. I have a GIAC ST 1 and an AFE intake with noise pipe delete. I can reset it but it returns after a day or so.
View 1 RepliesI have a 99 f150 with the 4.2l v6 with a 5 speed 173000 miles. I picked it up not to long ago. When I first got it it had both the P0171 & P0174 lean on bank 1&2 it was also siting for a while. I replaced the fuel filter which was filled with black fuel, also changed the PCV valve, cleaned the MAF sensor, and changed the oil. I cleared the code, drove it for a little bit and the light came back on after 20 miles.
I then proceeded to replace the upper and lower intake manifold gaskets. Upon doing that i noticed that i was missing one of the linkages for the IMRC. I went to the junkyard and pulled off another linkage rod off the same motor. ordered new plastic clips, put the IMRC on cleaned everything up and began putting it back together. I also cleaned the Injectors while i had them out as well and put in new spark plugs and wires.
Put everything back together. code was cleared since the battery was disconnected. drove it and then the engine light came back on again. this time it was only the p0174. so i then both the upstream and downstream O2 sensors on bank 2, reset the code and it came back on again. I'm lost.
I have been getting a P0171 and a P0174 code lean bank 1 and 2 sensor 2. I have replaced all 4 censers the 171 is gone but I keep getting the P0174 and it only comes on when I am on the highway after driving around 10 miles or so i got a freeze frame of the data when it happen.
View 6 RepliesI just bought a 99 f150 and the check engine light came on with code p0171,system too lean bank 1. It runs and drives fine but has a strong smell of gas when I shut it off.
View 4 RepliesI recently had some work done on my 2001 VW Passat 1.8T (timing, water pump, major tune up). IT had 72K miles.....
Now I'm getting the following:
Code P0171 Too Lean (Bank 1).
Emission Light turns on / off.
Check engine light comes on and stays on after about 20 miles. Can this be the oxygen sensor?
2003 f150 supercrew with 166,000 miles on it. Daily driver. Service light randomly comes on and when code reader was put to it shows "left bank running lean." Will clear it and will randomly come back on. Truck seems to be running fine. No issues engine. Bad sensor? Or bad injector? Maybe way to test?
View 1 Replies2000... I have a code P0171 bank 1 too lean. My question is does this exclude anything that will effect both banks? If it was MAF sensor or fuel filter would it set code and say banks 1 and 2 running too lean? In which MAF sensor ohms out correctly. I cannot view fuel trim files. I have looked for a vacuum leak with no luck. I got some cigars to try to smoke it to see if there is any vacuum leaks. Trying to narrowing what i need to checks.
View 19 RepliesI have a 2006 Chevy Trailblazer LS/LT 4.2 liter 2wd. I have been trying to get it smoged, but can't clear the code. P0171 - Lean Bank 1.
I've been having a parts throwing contest with it, but it has been winning and my wallet is losing.
I have changed the air filter, cleaned the MAF sensor, changed both O2 sensors, changed the secondary air valve and relay. I've done the carb cleaner spray test around the intake and vacuum lines, with no spikes in RPM.
Most recent try was a couple bottles of Techron concentrate with premium chevron gas.(still waiting to see if the code hits again)
Next steps are checking the intake bolts(to see if they are torqued) and intake gaskets, check for exhaust leaks at the exhaust manifold, and checking the MAP sensor.
Freeze frame data from the most recent hit on the code is below.
***Fuel system 1 - CL***Fuel system 2 - NA***Calc Load(%) - 30.2***ECT(deg c) - 48***STFT B1(%) - 3.9***LTFT B1(%) - 22.7***MAP(kPa) - 33***Eng RPM - 809***Veh speed(km/h) - 0***Spark Adv (deg) - 10.5***IAT(deg c) - 20***MAF (G/s) - 5.82***TPS(%) - 15.3***Air status - NA.
We have a 2003 Passat 1.8t. Had the Check engine Light come on. Went down to AutoZone and hookeded up the OBDII reader. Came up with P0171, Fuel System for Bank 1 was too lean. Probable causes:
1. Fuel Pressure of MAF (If Bank 1 & Bank 2 set codes together)
2. O2 Sensor
3. Ignition Misfire
4. Fuel Injector Problem
Car has 60K - has always run well. Wife says she thinks it's running a bit sluggish. I rarely drive the car, but I think she's right. Car is not missing or running rough.
I cleared the code & started the engine; Check Engine Light is off; then looked at the codes and I find a P0171 (Pending). She tells me that the light has been on before & then gone away. So I guess it clears itself, but eventually comes back.
Well I got the ubiquitous "Bank 1 Too Lean" code this morning. Yesterday I changed out the PVC Valve, Elbow and Hose assy.
I changed out the hose from the intake to the canister purge valve on the firewall next to the master brake cylinder, that one was like dust.
Today I'm changing out the rear O2 sensors, but I may change out the fronts when they get them in (very rural area hear).
I'll keep looking for vacuum leaks and change out the MAF sensor. I hate to think it may be the intake....
I've been having this problem since I've gotten the truck about year ago. it has very high long-term fuel trims and it seems no matter what I do I cannot get them to go down my fuel trims at idle are 39 Bank1 and 33 bank2 they go down to around 12>7 while driving what could this mean. And even weirder occasionally I get Bank 1 or bank 2 too lean codes at idle when cold starting???? 1997 Ford F150 4.6 ......
View 7 RepliesI have a 2002 prius with 130,000 miles on her, and so far so good except for a small problem for the last three months, I get an intermittent P0171 code. I know it means Lean Condition in Bank 1. However, I can run the car for weeks without it coming on. If I go full throttle getting onto the highway for example it may come on, but even then its not all the time. Not sure why only full throttle. But if I drive her gently, I will never see the CEL at all.
Fuel economy is around the usual for me at 46-49 mpg with average speeds of 75-85 mph. I don't think its vacuum related.
I keep getting a lean bank code. I have cleaned tb and replaced one of the rubber lines. It only comes on when I take a good ride with the truck. Not sure what else it could be. I'm thinking O2 sensor maybe.
2008 F-350 5.4 3V. 65k miles
I've searched for this and haven't come up with much other than the same error code for a bunch of other vehicles, and a bunch of different responses. My Tacoma is a 2000 PreRunner, 3.4 liter engine.
The exact code I get it is:
P1071
bank 1 system too lean
What this could be?
I have a P0171 code (lean bank 1 sensor 1) on my 2002 toyota camry 4 cylinder. I don't have any other codes except for an unrelated P1780 neutral safety switch code. It has had both codes for over a year.
I have replaced the fuel filter, the upstream o2 sensor, and the PCV valve. I also cleaned the MAF sensor. The mechanic performed a smoke test and found no vacuum leaks. Did a fuel pressure test and it's normal. Mechanic thought it would be fuel pressure because the car starts a bit slow when cold, but nope. The car runs great and still gets great gas mileage. I've never experienced a misfire in my 12 years of owning the car. I am asking because I am at a loss as to what it could be.
I bought 04 Lariat (5.4 3v around 100k miles, Roush Off Road side exit exhaust, DWV intake mod, SCT 3015 tuner).
The truck has had a miss on and off for around a month I've changed plugs and tested all the coils. Which cured the problem for around a week, the FPDM had some white stuff on back and soft spot but not ate through. The only Check Engine Lights have been bank 1 to lean (which went away as soon as it came. But yesterday and today I've got bank 2 to lean.
Below is a quick data log pull... The misses is about ready to ship her out if she don't straighten up..
My vehicle is a 98 F150 5.4 ltr Triton. I got a check engine light on and the error is "bank 2, system too lean." I read that this can be caused by a few different things like vacuum leaks or fuel filter and so far I haven't been able to narrow down. It started with occasional shaking at idle and its happening more as time goes. When at idle it often makes a sound like slurping the bottom of a drink with a straw and shakes intermittently. The fuel economy seems to have gone down. Sometimes it seems like it almost dies in idle, but always keeps running. It runs great when I push on the gas.
View 4 RepliesI got an 04 Nissan Sentra and I got a (P1273 Nissan - Air Fuel Ratio Sensor 1 Lean Shift Monitoring Bank 1) code that popped up on it. Looking to see what the probable cause for this code to pop up? Is this a rare code that popped up on this car? There's no noticeable symptoms going on with the car.
View 9 RepliesSo I just replace my Cat. Converter with all new sensors in them. I just replaced my spark plugs. (I'm knocking out these check engine light problems) and I think I'm getting close to the root as to why these other parts went bad. Why my o2 sensor would be stuck on "lean" ....
View 5 RepliesWorking on my son's 2001 sport trac. 200K miles but it has always been a great running truck.
I have two CEL codes:
P0171 System too Lean (Bank 1)
P0174 System too Lean (Bank 2)
I have found several issues so far, but have yet to get rid of these pesky codes.
So far I have changed:
- Intake Gasket - I had coolant loss which replacing this gasket fixed.
- PCV Valve and Hose - valve was damaged and the hose leaked.
- EGR Valve - Valve was leaking
- Fuel Filter
- Mass Airflow Sensor
The engine does appear to be running much smoother now, but the lean codes remain.