QuestionHad an alternator replaced and digital compass started always pointing west,
very shortly after the engine started missing at around 50 MPH when accelerating. Replaced fuel filter but no change. Unplugged battery cables and
let sit for a day, then reconnected and it ran fine for a week. Exactly a week
later it came back worse and now misses after running for 10 minutes down
highway on any acceleration. When it down shifts to pass a car, it doesn't
miss at all. Guy at Autozone wouldn't sell spark plugs to "shade-tree
mechanic" (old mech teacher). So assumed it didn't need plugs. Recently now
if accelerated while it is missing long enough the check engine light will flash
but not stay on. Also it has been through several tanks of gas since so ruling
out bad gas for now but gas milage had dropped from 15/16 mpg to 12/13
mpg. Almost thinking now that it's computer related or failing sensor related,
but what and where? Any ideas?
AnswerGo to another parts store and have the engine codes read. It's probably not a failing computer. I can't speak for the hesitation, but when an engine light comes on and off it usually means one of two things. Replace all of the oxygen sensors. It's probably only one that has went bad, but my theory with them is that they are all exposed to the same conditions, so replace them all. I also replace headlights in pairs. Please give me the code, not the parts guy's interpretation of what it is. Don't worry if the lights not on, it is stored in the computer. The only other thing that causes the engine light to come off and on is the idle air control valve, which I don't believe is you're problem. Please let me know the codes.
