Serious headache with my 2000 2.7L reg cab...I replaced my entire exhaust a few months ago with a Dynomax 'super turbo' system. Eliminated the front cat. Finished it in a day in my driveway. Initially the smaller muffler sounded much louder than I'd expected, but I quickly grew to enjoy the sound. Everything sounded tight, even though the hangers weren't lined up and the whole system was wired up.
The problems started roughly two weeks later when I took it into a shop to have the hangers welded into the right spots and to have my Doug Thorley 'headers' installed. I also had them weld shut the weep hole on the muffler.
Immediately after leaving the shop I noticed what sounds like a leak from somewhere near the 'headers', either at the engine or the front pipe. It becomes noticeable at 2000rpm and gets worse from there. Of course I took it back in and they assured me there is no leak. The sound is like a "whispering", maybe even a gasket leak. I had three gaskets on the manifold/front pipe connection initially, one flat gasket that fit around both the pipes and two individual crush gaskets. The shop did away with the first.
The noise did not exist before the 'headers' were installed, and my shop is pretty adamant that there are no leaks. I'm wondering if anyone has had a similiar problem. Maybe the heat shield missing from the new 'headers' allows the noise from the fan/belts escape and be heard? EGR problems?
Any help or advice would be greatly appreciated, I've put a bit of money into this exhaust and I feel like a moron, thanks