Hi I have a 2005 Mazda Tribute and have the code p0191 p0171 and p0174

Question

I have already changed all 4 O2 sensors,fuel filter, air filter,MAF, and all the gaskets for the manifold and injectors

Answer 1

Hi there,

I would check the fuel pressure next. It's affecting both banks of the engine so it's possible you have a low fuel pressure issue. Also, check for a blockage in the exhaust. Sometimes this will cause the lean codes because the exhaust is blown back into the engine so the sensors read lean.