Car: 1998 Civic LX d16y7

Short Version: I put an after-market exhaust (new header + new cat + new cat-back) on my exhaust and used it for a while. Today I switched back to the oem exhaust manifold + oem cat + oem cat-back. When I started her up, she started smoking out what appeared to be the exhaust manifold and dripped water out of the down-pipe to mid-back connection.

Long Version: About 1.5 years ago I put the above mentioned after-market header-back exhaust system on and she worked like a charm. Unfortunately I live in California which means that even though all my parts are CARB legal, I will still fail smog because of the "visual inspection" which mandates that all parts must be oem. I swapped the oem system back in exactly as I had taken it off--I kept all the same parts from 1.5 years ago when I took them off. When I started it up, after about a minute of warming up I began to smell a burning scent, it smelled most like burnt electrical wire insulation and i began to see smoke emanating from the hood. I opened it up to find the smoke mostly around the exhaust manifold (which on a d16y7 is directly welded to the cat with no flange in between). It doesn't appear to be overheating and I also don't have a CEL... yet.

Question: Will it just go away? Is it just cause the cat's been sitting for a while without use? should I buy a fire extinguisher?

I hope I posted this in the correct place. I googled the topic to no avail.
THANKS FOR THE HELP.

 

it will more than likely go away. btw... if you are interested in sellling your header... pm me with a shipped price.

 

I'm hoping that's the case--and Sorry, I'm actually just gonna throw the header right back on once I get the car smogged.

 

Make sure nothing is touching the manifold, especially the cat, and it will probably go away. I bet it's just dust or oil or something harmless.