Could oil in spark plug holes cause codes P1028 and P1071 to pop up? Techs can find no reason for these codes to continue popping up, No vacuum leaks or air flow system problems, changed thermostat to a Kia part. I do need to get this oil problem fixed as well as timing belt that I have never replaced and am now over 100K mi. What might be an avg. Cost of replacing timing belt, water pump etc.
Are you sure it isn't a P0128? If so, the following things could be the issue: - Leaking or stuck open thermostat
- Low engine coolant level
- Insufficient warm up time
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Engine coolant temperature sensor circuit poor electrical connection
The same thing with the other code. Could it be a PO171? If so, check for the following possible solutions for a lean mixture: Clean the MAF sensor. Consult your service manual for it's location if you need help. Remove it and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect all vacuum and PCV hoses, replace/repair as required Inspect all hoses and connections in the air intake system Inspect and/or test the intake manifold gaskets for leakage Check for a dirty fuel filter and proper fuel pressure Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool If you have access, you may want to run a smoke test
As far as the codes you listed, I have no information on them.