2002 gmc yukon xl code po171 car shaking only in the morning doest shake after morning

Question

Get a code po171 only shakes at start up in the morning does fine the rest of the day no driving problems

Answer 1

Hi there,

This code is for a lean fuel mixture condition on bank 1. Typically when it's only happening on one bank, and it's only happening when the vehicle is first started it can indicate an issue with the front O2 sensor. If there aren't any other codes, I would start by replacing the sensor to resolve the issue.