Q: P12a2 p0171 car starts up then idles low

asked by on December 14, 2017

Car smells like oil from top of engine. Car starts but idles very low and stumbles bad. Check engine light codes are p12a2 and p0171 and p0300

My car has 138500 miles.
My car has an automatic transmission.

Code P12a2 is related to the fuel rail pressure sensor which reads the fuel pressure in the fuel rail to ensure that the proper amount of fuel is making it to the fuel injectors. Code P0171 relates to a lean condition on one bank of the motor, which is likely related to the fuel pressure issue. Code P0300 relates to a misfire, which is also likely related to the lean fuel condition. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect the vehicle.

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