p0300 and p0171 along with rough idle-

Question

2005 Chevy Tahoe Z71 rough idle and showing codes P0171 and P0300

Answer 1

Hi there,

P0171 is a code for a lean fuel mixture on bank 1. This could be the cause for the P0300 multiple misfire code. It's very possible you have an intake manifold gasket leak causing the lean condition on bank 1. Start by checking for vacuum leaks.