Cadillac Repair: Cadillac 90 Backfires, oxygen sensor, cadillac deville

Question
I recently bought a 1990 Cadillac DeVille 4.5L with 120K miles. I was driving this car from NY to GA and the muffler blew up. I got a new muffler yesterday and I was again going on a  highway when the new muffler blew up again. Seems like alot of pressure is building up. I noticed that just before the muffler blew up, the engine power was acting erratic. After few seconds it blew up with a big bang ! After this the car was driving fine (ofcourse with alot of noise) but again every 50 miles or so it was making 4~5 big bangs with a loss of power but then it would drive fine.

BTW, "Get engine service light" stays ON all the time. Does it indicate that Oxygen sensor is bad ? If Oxygen sensor is bad, can it cause this problem.

I would appreciate any help regarding this matter.

Thanks in advance.
-Anuj
anuj@connectom.com


Answer
Hi Anju, Sounds like the engine is running rich/useing too much gas. The service light will come on for many differant reasons one of which is a bad oxygen sensor. Yes it is possable that the oxygen sensor is bad but there are other things that it could be as well. The first thing you need to do is get the codes read because that could lead to the repair. You might want to go to a Caddy dealer because they would have the best chance of repairing this problem. Otherwise look for a shop that displays the big blue ASE gear. I wouldn't be surprised if you needed a catalytic converter as well as a muffler. Hope you get this resolved soon. Bill