new to GMC

[zack tinnin]

Haven't had a GM in years, so language is new to me. I just bought a '97 Sonoma. Service engine light came on, code P0171. I don't know what

fuel system trim lean (bank 1

means. Please help!

 

[Molson02536]

Haven't had a GM in years, so language is new to me. I just bought a '97 Sonoma. Service engine light came on, code P0171. I don't know what

fuel system trim lean (bank 1

means. Please help!

Being lean on one side could be that the MAF (Mass Air Flow) Sensor is dirty or faulty but in most case both side's would show a lean condition.

Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.

There could also be a vacuum leak downstream of the MAF sensor and at worst, the puppet valve to your fuel injector is going bad or clogged with carbon and will need to be replaced.

Start with the simple and clean your MAF sensor and give your Sonoma a http://www.seafoamsales.com/ treatment. Use one whole can in the gas tank and the other for the vacuum line.

Good luck and keep us posted.

Molson02536