2002 5.3 chevy idles high

Question

Its give codes P170 P174. It drops back down when I shut it off and reatart it. What can be causing this?

Answer 1

Hi there

The code points to a lean fuel mixture on bank 2. It is possible you have a vacuum leak which will cause high idle as the computer adds fuel to try and compensate for the unmetered air.

P0174 CHEVROLET - Fuel Trim System Lean Bank 2

Read more: https://www.autocodes.com/p0174_chevrolet.html