just installed an ss autochrome header and exhaust (pipe containing the flex joint) today; had little difficulty. feels great except for a strange sporadic buzzing noise at lower RPM's when off throttle.

after driving around and looking under the car, looks like perhaps when the front suspension is loaded, the exhaust could be rubbing against the front swaybar and making the odd resonant noise. could also be high enough now that it's rubbing against the bottom of the block; up to this point, it'd been hanging because my flex joint was destroyed.
it's fine at speed, but quite noticeable when slowing for a traffic light down into 2nd-1st, etc.

anybody else had any problems like these? thanks!

not really..u might need new hangers by the cat

its a leak, i have the same noise

its a leak, i have the same noise

you figure out where? i hear it mostly up near the foot well, so i guess i'll be checking to make sure the header to downpipe nuts are tight. do these gaskets maybe take some time to seat? pretty sure we torqued everything properly.

also noticed that 1st gear is MUCH SHORTER, i guess from the extra low-end power. it takes ninja skills to not grind 2nd when upshifting now; i can't shift into 2nd after ~1900 rpm. it'll take some getting used to.

could be a crack or those shitty bolts they give to hold up secondary

problem confirmed: hitting the front swaybar just back of the flexjoint.

solution: took all the wrap off that section, loosened the nuts between the headers and downpipe, and pushed on the exhaust toward the passenger side while re-torquing them. it's still only got about 1 cm clearance, so i'll probably get a new swaybar.

took it for a spin and the buzzing and rattling is gone completely. i'm really psyched. 2nd gear is still super crispy; i think my synchro may be shot and the timing is just a coincidence.

thanks to all who put in their two cents.

PS:
i think the swaybar clearance problems might have something to do with it being the 2.5" pipe. i'm not sure if anyone else has had these problems, but i think it's worth noting for anyone else thinking of installing the 2.5 with a stock swaybar.

also, make sure you torque down the wideband O2 bung plug. not doing so can result in losing it on the highway (how about that?) and a really noisy exhaust leak.
might also be good to know that if you need a new plug in a pinch, an M18 x 1.5 drain plug (oil or tranny) for a variety of vehicles will fit the threads; got mine at autozone and passed inspection 10 minutes later. w00t!