Smoking Problems!!!

[nissandrift]

This morning I noticed my car was smoking a lot more than it used to, and Im not positive if its because the stuff Ive done in the last few weeks. I put on a test pipe last night, and changed to Mobil one 5W30 a few weeks ago. I changed my timing to about 20 degrees BTDC last night, turned out it was almost 29 degrees. My car seems so much slower driving home, but I was thinkin that was due to the test pipe problems. When I tried to take m cat off I broke off the 2 manifold side bolts, and couldnt budge or break the other side. I had to drive a few mile open manifold to my friends lift to torch it off. Any suggestions?

[[s3]]

Black smoke?Blue smoke?White puffy smoke?

[nissandrift]

Update: I just got home and checked. Its not smoking now, but now it seems like the exhaust is plugged. I think theres something stuck in there. What is suggested to get it out? Im thinking a shop vac on the cat side, or maybe compressed air through the exhaust.

[Soy]

...somehow I envision this happening...