Error Code P0171

[rburro2]

I got error code P0171 after I replaced my air filter. It is not anything hitech, just a Fram ProGuard filter. P0171 states Bank 1 lean. The Explorer still runs great. No power loss. I have triple checked the air box installation verything is installed correctly. I've disconnected the battery so the ECM can reset. Does anyone know what else would cause this? The fact that I just changed the air filter wants me to think it is that, but common sense tells me it shouldn't make a difference.

 

[Rcflyer330]

how many miles are on you explorer? usually a p0171 code means an o2 sensor is going bad. try just deleting the code with a scan tool and see if it comes back if it does then i would guess its an o2 sensor.

 

[rburro2]

It has 155,000 miles. I deled the code and it came back. I just thought it was related changing the air filter. Since it hppened right after

 

[Rcflyer330]

With that many miles I would definitely say its the bank 1 sensor 1 o2 sensor.
Could also be a exhaust leak or other vacuum leak. A P0171 code means there is too much oxygen in the exhaust but most likely its the O2 sensor going bad.

 

[rburro2]

Thank you. I'll check it out