toyota corrola 2009

Question

p0171 code, where is the o2 sensor located and how can i tell witch one i need

Answer 1

Hi there,

This is usually a code caused by the front O2 sensor if the sensor is in fact causing it. this is located in the exhaust manifold before the catalytic converter. I would also make sure to check the fuel pressure, the mass air flow sensor and check for any intake manifold vacuum leaks prior to replacement.