P0171 Volkswagen -

Question

When multiple codes come up with the check engine light, can this be due to using regular gasoline 87 Octane for long period of time? It is on 1.8 Turbo Jetta which should use premium gas 91 Octane. The codes are PO171,PO300, PO301, PO302, PO303, PO304 & PO507. The care runs fine and there is no hesitation. Reading these codes appears that it can be from a fuel issue. I appreciate any feedback or thoughts.

Many thanks!

Answer 1

HI there

The p0171 code is for a lean fuel mixture. This could be the cause of the misfire codes as well. I would check for intake manifold vacuum leaks, if there aren't any, then it could be low fuel pressure or a problem with the mass air flow sensor. Either will cause the lean fuel mixture code. Once you resolve the lean code, the misfire codes and the P0507 idle code should dissaper