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 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.
Working 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.
2003 Sport Trac. My car was not starting, told my fuel pump, replaced twice and nothing. Found out about inertia switch and changed it, now car runs.
Before this switch blew out my car was running perfectly, no check engine, nothing. Now i have changed my fuel pump twice and put a brand new fuel filter in and soon after i get lean codes P0171 and P0174. My fuel pressure is 60psi at idle and drops to 0 after about 30 seconds when the car is shut off.
A lot of my intake is new since i did have a vacuum leak before, so i do not suspect that is it, especially since this happened after the new fuel pump. I am completely stuck as to what i should do. And i get hesitation when trying to accelerate sometimes
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 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.
My 04 Explorer 4.0 has been giving me the bank 1&2 lean codes. It is the fully electronic throttle body not mechanical. It seems from reading that in 04 is when they switched to the electronic version. Here are some things I have done to resolve this. I created a diy smoke machine from a paint can and air. I found a leak by the egr.
I replaced the egr and gaskets, along with the metal part that goes into the throttle body. I replaced the pcv and hose(although it looked fine). I replaced my intake gaskets. I replaced the MAF sensor.
Before all of this my lt fuel trims were +25 for both bank 1 & 2. After doing all of this my trims did come down a little to Bank 1 +16 and bank 2 +23. I dont know what to check next!
2003 Ford Explorer, with P0171 and P0174 codes, common problem, as I have read. I pulled the cover over the engine off, and I immediately found the likely problem. There is a hose/connection that runs from the valve cover on the right side, about 6 inches behind the oil fill tube across and looks like it comes into the Carb. Where it turns to come into the carb is a rubber elbow. This elbow has a hole in it. Temporarily I have used electrical tape, but when I run the vehicle, I see the elbow begin to collapse. I believe the elbow is getting weak with age, plus the hole/tear doesn't work. Anyway, what i the part number, or what this is called. Hoping Advance Auto, or Napa will have it, just don't know what it is called, and can't figure out the part number. Otherwise I will pull it off tomorrow and take to advance and see if they can match it.
View 5 RepliesAfter 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'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 1996 ford taurus lx dohc v6 3.0.. I keep getting codes p0171 & p0174 System Too Lean (Bank 1 and bank 2. I check for air links and i did not find any..I never got that code tell i replace the MAF sensor..
View 7 RepliesI own a 1998 Mitsubishi Mirage with about 190,000 miles on it. The engine light has started coming on and I get three codes:
P0170 Fuel Trim Bank 1P0136 Oxygen Sensor Bank 1 Sensor 2P0301 Cylinder 1 misfire
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I 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?
I have a 1999 Ford Expedition with 163,000 miles.The vehicle registers a service code of P0171 and/or P0174, lean mixture.The vehicle starts fine, but may stall or hesitate when first started or at red lights.While driving, there is no issue.
I just replaced the MAF sensor and the EGR sensor, but no change in the condition.In 2007 or 50K miles ago, the oxygen sensors were replaced. What could be the problem or solution?
So 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 RepliesMy truck have 4 codes p0174 and p0171 system too lean bank 1 and bank 2, and p0345, p0349 camshaft position sensor bank 1 and bank 2.
View 3 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.
So the check engline light came on, and i hooked up a basic OBD II reader to the car. Out came codes P0171 and P0174 and it read "system too lean (bank 1)" and (bank 2) respectively. What does they mean?
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