Just recently, whenever I start my car after it has been sitting for a long time (8+ hours), it idles a little rough. When I start accelerating, it has a small stuttering problem from first to second and not so much from second to third and so on. I have an A4 BTW. After about 3-4 minutes of driving, this symptom disappears and I have no problems until the car has been sitting for a long time. It almost seems to me as if this problem lasts long enough for the AIR pump to heat up the cat. Anyone experience the same problem? And was it the cat fixing to take a dump? TIA

 

Someone correct me if I'm wrong, but a clogged cat would cause a noticible loss of power throughout the powerband, not just for a few minutes after warmup.

 

I had a clogged cat and it resulted in a major loss of power across the powerband and no change when warmed up.

 

My cousin had a clogged cat and the car wouldnt shift out of 2nd to 3rd (A4) because the engine wouldnt be making any power. He bought a $80 universal cat and 2 adpaters and was set.

 

i think my cat may be cloged after 174000 miles, i think i may just "punch" it out. Can this be done with the y-pipe still on the car? What should i use, i have a 1 1/2' screwdriver that might work.

 

You can just use a broom stick to knock it out, then start the car and let the exhaust blow the rest out.

 

would the exhaust blow all of the crap out? Im afraid that some sht might get stuck in the y-pipe and makee things worse. What is actually in a cat? Its like mesh of some metal, can't remember which one tho.