Had the fly wheel replaced. Runs a lot better. Still having an issue where it won't run if the hose from the pcv valve is connected to the intake. CEL is no longer on but it has a high idle rev. Could it be the TPS sensor or the IACV? Just cleaned the entire throttle body and IACV.

 

The usual cause of a high idle is a vacuum leak, easily explained with the disconnected pcv hose. Did you replace the pcv valve? Check the pcv hoses, too.

 

Yes, new pcv vavle and the hose is good along with the rubber boots. The reason its disconnected is because when its plugged in the car will stall. Out when given some gas. It seems to be deprived of oxygen.

 

Both the throttle position sensor and the idle air control motor are involved in the computer's calculations to maintain idle speed. So one or the other or both could be involved, but there could be other factors, like a weak spark or fouled plugs or fuel injectors. If you can't get a hint from the engine codes (which might be present regardless of whether the CEL is lit), then replace things starting with the cheapest first.

 

Just an update, seems the timing was off causing the misfire. All hoses are now connected but still seems to run a bit rough. Mechanic says the engine may of been damaged due to running it with the timing off.

Recently the P0491 code popped back up. Anyone know the cause of this? Its a CA emissions car. Mechanic said its used to pass smog and shouldnt cause to much of an issue on how the car runs. Is this true?