So 2 days ago I did a muffler delete on my 06 tC and so did my friend on his 06 tC. After about a day we both noticed a squeaky noise coming from under the car. It's very high pitched and annoying and very noticeable when riding with the windows down. This noise is bothering us so much and need help figuring out what it could be and how to fix it. We've already looked up probable causes such as a loose heat shield but both of ours seem to be tight from what I see. SOMEONE PLEASD HELP US!

 

Did you guys figure it out?
Both your's and your friend's TC are squeaking?
When does it happen? Is it isolated to the rear of your car?

 

So basically, you just unbolted your mufflers and left the midpipe hanging? My guess is that it's related to your rubber hangers/isolators. By unbolting the muffler you eliminated 3 of the 5 exhaust hangers. Basically, the entire midpipe is being supported by just two hangers at the front of the midpipe, allowing the the back end of the pipe to sway back and forth. You are stressing other connection points of the exhaust as well. Buy a cheap bolt on axle back from ebay and put that on.