I am having a new 4.0 installed in my '99 Cherokee. During the removal of the old engine I found out that the downpipe was damaged. The pipe has what looks like a small pre-cat welded into it. I can't find a NOS pipe anywhere and all the aftermarket pipes lack the pre-cat (if that's what it is). California is crazy-strict on exhaust modifications so I need to find out if the pre-cat looking bulge in the downpipe is actually a pre-cat or just a resonator. Does anyone know what that bulge in the stock downpipe actually is? I am trying to keep this XJ California smog legal so any help would be greatly appreciated.

 

Found out what it is but no idea where to find one. One source shows it discontinued.

http://www.jeepforum.com/forum/f11/9...sytem-1443774/

 

Thanks. That answers the question. I need the stock downpipe to be California smog legal. Looks like my pipe wasn't damaged after all. The dent before the O2 sensor that my mechanic thought was damage is actually supposed to be there. Good news!

 

Very good.
Like to have a dollar for every time someone's posted that their down pipe got dented some how. LOL
Is a heck of a looking thing.

 

Yeah, it does look wrong. I wonder how many of those pipes have have been replaced with aftermarket units for just that reason. The Internet can be a wonderful thing. Saved me a few bucks this time.

 

Ca exhaust restriction requirement. Sometimes these are dented in another piece of pipe that slides into the main pipe and you would never know it was there until you cut it for some reason. Why??? Dumb as...