I recently had to get a new muffler for my '89 IROC after a rear-end collision. The guy who welded it on also got the actual muffler for me; we had asked him to find a stock fourth-gen exhaust to a Z28 or SS car. What he fished up was, he claimed, fresh off of an SS Camaro (didn't say what year)... he described it as a "stock performance exhaust".

However, I just looked under my car and noticed that one of the pipes has a date printed on it: 09/14/2004 . I'm thinking a true SS muffler wouldn't have a date that recent on it. Does that date pretty much confirm that it's not the fourth-gen exhaust I thought I bought?

 

manufacturers are required to produce parts up to 10 years after the car stops rolling off the line.

 

I didn't consider that. But since this guy does a lot of aftermarket exhaust jobs, I just figured that what he got me was the "leftover" from one of those aftermarket jobs.

I'm just starting to wonder, since I had hoped that the stock fourth gen exhaust would be better flowing than what I had on there before (it was a Midas muffler, I believe). But the ***-dyno feels that my car actually has a bit *less* power, especially in the low end.

 

well you probably paid the same amount for this OEM muffler than you would have for a performance muffler from dynomax, hooker, or borla.