My Subie has had an ongoing exhaust problem for a while now. This car's saga is long, but I won't take up space here.
Noisy exhaust, gray-blue smoke out the tail pipe, had to keep my foot on the gas on start up to keep it from dying, possible choke issue as well, etc.
After a long drive (500 miles) to visit my daughter, the problem seemed worse.
A couple of days later, I heard a soft pop and the car seemed to run much better.
However, it started to auto-rev at start up—up to 2500 rpm then back down. Once the car warmed up and I started driving, it seemed fine.
A day later (yesterday), it started to auto-rev whenever I idled.
Tonight, on my drive home at highway speeds (55 mph), it started auto-revving at those speeds, and was going into the red. I had to pull over and stop three times within a couple of miles to let it calm down.
Also makes an horrendous grating squeal when revving, as if a belt is rubbing hard.
Help!
Not a mechanic and I wouldn't know what looked normal and what didn't if I were to crawl under there or look under the hood.
