There's well over 2,000 diagnostic fault codes that could be set when the Engine Computer detects a problem. About half of those refer to something that could adversely affect emissions, and those are the codes that will turn on the Check Engine light. Start by having the codes read and recorded. They never say to replace parts. They indicate the circuit or system that needs further diagnosis or the unacceptable operating condition.
Thursday, March 3rd, 2016 AT 12:24 PM