Jay1

My truck will set the check engine light on with the code p0171. Which means fuel system lean on bank 1. Here's what it doing to me. At first the light would come on and it still ran okay and light would turn off by its self. I removed the battery and now its running badly. The first thing was the check engine lightcame on saying it couldn't read engine temp but mu gauge worked just cine. The light will stay off at times but its not running right. When the light comes on now it will barley run around 1800 to 2200 rpms. I have check a couple of sensor but I can't get to some with out removing parts. I just put a new down stream o2 sensor in. It wasent working at all. Im just looking to see if anybody might know what sensor it might be or what it could be so I can get if fixed. Let me know what you guys think it could be. Thanks.

Jay1

Anybody

mattbatson

do a search and you will find some good info on that code.

many have found that with that code, replacing the MAF sensor did the trick.
Even after cleaning the old MAF and having it test good, it was only after putting a new one on that it fixed anything.

Although, my first guess with you're problem is a vacuum leak.
I would go through every single vac line and inspect/smoke test...etc.
Also, make sure your rubber intake hose up to your intake has no dry rot cracks or such in it.

chop130

i had the same thing happen with the lean code and i had to clean the air mass flow filter a couple of times before the dam thing went off