Don't visit this forum much as I'm not a huge racing fan and own a sort-of  poochy car (1996 Geo Tracker- go ahead, laugh! Be my guest!), but I wanted to share this little moment with all the shade-tree mechanics out there...
Last summer, probably because the cat. clogged up after 130,000+ miles, the flange at the top of the header pipe (where it mates with the 4-to-1 manifold) cracked all the way around, leaving my 1.6 sounding like a Harley with short pipes. Had to remove the entire exhaust sytem from the manifold back in one piece (long story) so I could weld the flange back on (could not find that pipe ANYWHERE, for any price!). Got it all back together, and it was still a bit noisy. And a bit fumey... Also failed NJ inspection. Hmmm... what I didn't realize until I replaced the cat. a few weeks ago was that there's supposed to be a "doughnut" in there (soft metal ring with one flat side and one convex side) to act as a plug in this spring-loaded joint. Got one shortly after installing the new cat., but put off installing it as I also broke one of the bolts that thread into the manifold (D'oh!) to hold the header on, and was putting off dealing with that ( !).
Put it in this evening, and although I still haven't repaired that bolt, it sounds much, much better. Guess I'll take it to a shop soon to try to clear that engine light (probably the O2 sensor now, but who knows? I don't have the test gear to find out) and get it inspected, then at last I won't be begging for a ticket every time I hit the road in that thing.
Not the most exciting car story, I know- but the subject title really pulls it all together...

lol, sounds like a fun time working on cars...

It is always a good thing to be able to weld.. Through my current employer I've been able to learn all about tig, stick and spot welding along with a variety of metal working techniques..

good luck keeping it all legal, I'm working on that myself right now with my comet....expevt details and photos in the next few days..