Q: Engine light p0171

asked by on

My 4Runner has a check engine light code p0171, my MAF is relitively new from a wrecker and I clean it periodically, I used throttle body cleaner to try to find a vacuum leak couldn't find anything, replaced the front o2 sensor still get the code also my 4Runners idles up when I coast to a stop sort of surging I'm not sure what to do,I ordered a second 02 sensor for the back, should I try the fuel pump or injectors? It is a 99 4Runner engine that I swapped into my 90 4Runner thanks for anyhelp!

As you may know, his code is related to a lean fuel condition which is normally related to many of the items you have listed. I would recommend checking the injector pulses to be sure they are providing enough fuel to the motor. Often times bad injectors can also cause a lean fuel mixture.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Engine light p0171

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Window stuck

These are two problems that will probably need to be addressed separately. The window being stuck may be caused by a bad regulator or motor, or even a switch. If the interior door handle is not opening the door, there...

Q: Car won't start after starting minutes before, battery not dead

Firstly, remove the back seat's bottom. Then listen near the fuel pump access cover when someone cycles the key on and off. You should hear the fuel pump come on. If not then you may have a burned out fuel...

Q: Rattle sounds undercarriage

There are countless potential causes for your noise. It could be anything from a loose heat shield, to a worn strut mount. I suggest you have a trained professional, such as one from YourMechanic, listen to your vehicle firsthand to...

Related articles

How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...