CEL P0171 Help please!

[fatwombat]

So I recently got the P0171 CEL on. I first thought it was my MAP sensor since I was getting a rough idle and the truck shut off on me. Bought a new MAP sensor and then five codes came in. one saying Bank 1 is lean, then the other saying Bank 1 is rich, then low voltage on sensor. I want to break things down and see if I can get this solved by tonight. There is no vacuum leak.

I am thinking:
Both O2 sensors
PCV Valve
Or I got a bad MAP sensor

Would like some guidance and support? Since I can turn no where else but the experts here!

 

[KGBIGCOUNTRY]

When was the last time you did normal maintance on the truck?

 

[fatwombat]

I would say about 3 months ago... Not everything was done but most stuff...

 

[KGBIGCOUNTRY]

When you put in the new senor was the battery unhooked? PCM reset done? Is the connection good and clean?

 

[fatwombat]

Battery was not disconnected but I did reset the PCM!

 

[KGBIGCOUNTRY]

Im courious if the new sensor got a spike in voltage when you hooked it up. The electrical systems on these trucks are sketch at best sometimes. Call the place you sourced the part from and tell them their new sensor is hay wire and needs to be checked out buy whoever supplies them. Get another one and have the battery unhooked to install the new one.

 

[fatwombat]

Yea I was thinking the same thing...

 

[KGBIGCOUNTRY]

Im leaning towards that being your issue because you got both the bank 1 showing rich and lean at the same time and the only thing changed has been that sensor.

 

[fatwombat]

Correct!

 

[ramhunter9]

P0171 1/1 Fuel Sys Lean

On top of this page we have trouble codes .

I will move this to the correct section for you .

 

[fatwombat]

I know but nothing helps me with telling me what the correct problem part is!!

 

[Redtruck-VA]

I don't have access to my data, so pulling this from my ass. But the sensor low voltage is also tied closely with fuel. I think I would reset the PCM check MAP connections, clear codes and see what codes pops up. Good luck..

 

[fatwombat]

The thing is I replaced the MAP sensor with a new one and clear codes. Then 5 codes logged. So Im going with the MAP sensor went bad or was a bad one!

 

[Redtruck-VA]

Makes sense, pls post the out come.
Thanks,

 

[fatwombat]

I will... I will be buying another sensor hopefully today!