P0171 CHEVROLET hhr -

Question

I have a 2011 HHR that is indicating a couple codes - P0171 and P0326

Answer 1

P0171 Fuel system lean

P0326 Knock sensor performance

When you get a lean bank this means more air than fuel, as a result you get a lean misfire, The knock sensor is only doing what it is supposed to do, and that is to retard timing when a knock occurs, Inspect for vacuum leaks that will cause a lean condition and also the fuel pressure should be with key on engine off 50 to 60 psi