Maybe someone crammed something up there. Symptoms match it. If you don't see anything there, the exhaust may be choked at some other point.
Hello all, I have a 1997 Subaru Outback automatic 4 cylinder 2.5 liter engine. Whenever I start it up, after a few seconds it stalls out. I've already replaced the fuel filter, the throttle position sensor, and the mass air flow sensor. I've also tried running the car with the oxygen sensor unplugged. That didn't make a difference. I am wondering if anyone knows what other parts could be related to this problem?