What are common reason why a check engine light comes on on a 1997 ford ranger
Malfunction in the engine management system, someone left the gas cap loose or its leaky, Overdue for service maintenance, problems starting....................................................................................... First you read the code, google it, read the book, test it, then consider the codes and their possible causes, pinpoint tests for hard faults..............ask your tech, or the recommended certified monitored emission repair shops in your state.or whatever. Throwing aftermarket parts at the problem guessing ? NO ! Seek the diagnosis from the emission people if you want to understand and stay legal for the least expense. They have to help. they have to directly affect the problem, their work can count towards a waiver if you have a failed test. You can call free, to get questions answered, google emissions authority, call, ask, get the steps, document, solve in the fewest steps. I have solved a few that way, saved time money, and frusteration, learned more about it.
I've seen angry confused idiotic and stupid, sat them down, made the phone call, had nice lady tell me their steps, saved them gas, time trouble books tools all that. 2 of them were no longer required to test. It's worth the 20 minutes to save days.
Thinking about your vehicle reminds me, does it have a driveability symptom to go with that light? Does the light stay always steady lit when the engine runs ? or what. Is the vehicle behind on maintenance ? Cold blooded? Old gas cap? Think about your symptoms, how and where you use it where you are, your climate, list your clues. If you can get the codes checked at the parts store, it can help, but careful buying things before diagnosing. waste of money.