I have a 2000 civic si and my engine light came on took to a mechanic and said my car was running to rich, and a fuel system malfunction, fuel system is all stock can anybody tell me what might be the problem. And also how can i check for a vaccum leak thanks.

 

You have a vacum leak if your car surges, and the reason your car is running too rich could be selveral things. One of your engine or emissions control sensors could be going bad or you might need to adjust the timing. Your mechanic didn't know the cause?

 

most likely i think its a sensor go the timing checked like a month ago i just need to find witch sensor it might be. any suggestions

 

Autozone can scan your obd2 ecu for free and find what the code is and what sensor it is.