1998 Chevy 5.7 misfire (P0300) and fuel system too lean (P0171 and P0174) trouble codes AFTER the intake manifold was removed. This is the same van that I shot two different videos on, one for each of my channels.

This car had multiple problems. In this particular video I will be showing you the cause of fixed lean oxygen sensor signals (both banks) and very positive STFT and LTFT numbers. I will also show you how to use fuel trim after the repair to determine if you have any other problems.

This is a Ford Expedition 5.4 with a vacuum leak causing "System Too Lean" trouble codes P0171 and P0174. In this video I will show you how to use freeze frame data and fuel trim numbers to identify a vacuum leak. Then I will be using water to locate the specific area of the vacuum leak.

This vehicle came in with a long history, a severe misfire complaint that two shops couldn’t fix, and lots of parts changing along the way.