p0101, p0171, p0174, and p0300.

Question

I went through emissions and my vehicle failed due to the following codes p0101, p0171, p0174, and p0300. I recently replaced the spark plugs, 2 o2 sensors in banks 1 and 2. The Mass Flow Sensor was replaced a few years ago, but never cleaned. Please advise what can be done to have my vehicle pass emissions

Answer 1

P0101 MAF (mass air flow) sensor range / performance problem

P0171 Fuel trim lean bank 1

P0174 Fuel trim lean bank 2

P0300 Random misfire

Have the fuel pressure check for this condition the specification are 55-62 psi. The MAF is a recommended to have cleaned it does get contaminated and when it does it under report which lean the condition,but it can not cause a P0300 (random misfire). Fuel pressure should be check and also the fuel pressure regulator for any leakage into the intake manifold.