P0171 BUICK - Ultra

Question

I have 1997 Park Avenue Ultra suplercharger. I replaced MAF, MAP, O2sensor(both), EGR, checked for any vaccume leak, still check engine light comes on after say about one minute. Any ideas.

Answer 1

P0171 Fuel system lean bank 1

How the idle? Its not rough or high? The throttle body,no vacuum leak, EGR no vacuum leaks,No crack at the exhaust manifold?On the bank 1 side? Injector all hook up? Then you go to the EVAP system. Plug the purge valve to the throttle body,clear the code,if it still comes on inspect the sparkplug condition,use the underhood information for sparkplug gap.it should be 0.060 in