I installed a magnaflow catted x-pipe yesterday, and noticed that I'm getting a rattle around 1500-2500 rpms (only when the car is moving not in neutral). My first guess would be the passenger side flange bolt where the cats meet the headers, since that bolt was a major pain to get torque down on. Anyone else have experience with a rattle after a mid-pipe install and have suggestions of things to look at? Heat shield maybe?

 

My catted SLP X-pipe has rattled since day one. I've checked to make sure it has a clear path so it's not rattling against anything. I've triple checked that all bolts are tightened properly. The rattle is coming from under my shifter (automatic) and I now believe that it has to be the harmonics (2nd or 3rd degree? I'm not sure) from the increased sound waves coming through the walls of the X-pipe.

 

Hmm, so I guess I was assuming the rattle would be a exhaust leak, but not necessarily right?

It's pretty annoying... I feel like there's got to be someway around this.

 

My rattle is not an exhaust leak, although it did leak initially before I tightened up the downpipe bolts properly.

 

Try making sure the heat shield on the cats is not loose. Had that happen to me.

 

Was it ever sitting in dirt/gravel? I had a rock in my prochamber, drove me nuts for week until I pulled it out again. Check to make sure your cats are intact if you pull it off. My cheapo ebay ones blew out after two years and I went O/R pipe for while. Sounds great but little to loud for a DD

 

hmm, if worse comes to worse I may take it apart and check it for gravel/dirt. Right now I'm leaning towards heat shield or improper torquing of the passenger flange.

I can imagine O/R pipe being too much for a DD. The catted x-pipe with Macs is already pushing the limits of what I'm OK with for the Daily driver, time for a 2nd car haha.

 

I think I tracked down the rattle to the passenger side rubber hanger at the transmission crossmember. The metal hanger welded to the x-pipe is in direct contact with the bolt head of that cross member. That's gotta be it... Now to just find a way to fix it, might have to bend that hanger.

 

You could add 12" resonators to your set-up. It quiet it down a little and give it a nice tone.

 

Hmm, how much did it cost to get your resonators installed?

 

Does the new x-pipe use the exhaust mounts on the tranny cross member? If not those could be the source of your rattle. They are a different metal and are not integral to the cross member. If they are moving around then they could be the source of your rattle.

 

I paid $145 parts and labor, but other shops quoted me anywhere from $175 to 250 parts and labor.

 

I think this is the source. It looks like the bolt on the cross member is contacting the hanger rod on the x-pipe. I think I'll have to come up with a way to bend the hanger unless someone has a better idea.