Bad pressure regulator symptoms that you could be experiencing are a no start, hard start, rough idle, a check engine light, fuel in the fuel pressure regulator vacuum line, failed emissions test, poor engine performance, and poor gas mileage. Some of the engine codes you might retrieve are P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, and P0172.

This article will help you see if it's time to replace the AC pressure switch in your car. The 4 symptoms of a bad AC pressure switch that you may experience are an engine light with codes (P0530, P0531, P0532, and P0533), the AC compressor not turning on, AC blowing warm air, and AC not working consistently.

Have you been driving with a bad purge valve? This article will help you learn 5 bad purge valve symptoms and trouble codes.