Q: codes p0174, p0302, and p2A03 read on code reader.

asked by on January 08, 2017

It needed 02 sensor I replaced it all lights went out and stayed out for 2 or 3 months Now I have three codes p0174,p0302,p2a03 help

My car has 75012 miles.
My car has an automatic transmission.

Hi there. What is happening is the codes are reading for a misfire on cylinder number 2 and the system is too lean on bank 2. Check the spark plugs and the fuel injector on cylinder 2 to see if they are working. The spark plug would be fouled out and not causing a spark. Swap the spark plug with another plug and see if the engine misfire changes to the other cylinder. If it changes, then the plugs need replaced. I recommend replacing all of the plugs with OEM specified spark plugs. If the spark plugs are good, then check the fuel injector on cylinder 2 by unplugging the harness to the injector. If the engine hesitates more, then the injector is working. If there is no change, then either the injector is not working or the cylinder has a burned valve or a stuck piston ring. To verify the injector, swap the injector with another injector and see if the problem goes to the other cylinder. If it does, then the injector is not working and would need replaced. If there is no change, then the cylinder 2 has a leak inside the combustion chamber and needs repaired. If you need further assistance with your engine misfiring, then seek out a professional, such as one from Your Mechanic, to help you.

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