I just had a quick question about clogged cats. My car has been running kind of slow for the past few months. From a stop to go it feels as if there is a moderate hesitation, which will go away when I reach the higher RPM's. Also, I have been experiencing the rotten egg smell of a clogged cat every now and then (probably a few times during the month...also did it while on the dyno).

My question is that for my cat to be clogged does it have to be producing the egg smell all the time or just randomly? Should I go out and purchase another one even though I smell this at random times?

Also, after inspecting my cat it looks as if it is dark and burnt up. Not just burnt like an exhaust leak would do but the whole thing looks as if it has been put in a fire (probably caught on fire). Again another sign to lead me to thinking it was a clogged cat.

I've read that loss of power, sound decrease, egg smell are all symtpoms. Just wanted some oppinion of those that have had the problem before I go out and buy another one.

O yeah...its a random tech. high flow cat, and I have been running rich before I got my tune.

Jp

 

How long were you running rich before the tune? Raw fuel into the cat is a sure fire way to melt it down. The symptoms you descripbe would lead me to believe the bricks in the cat could be melted.

An exhaust shop can drill small holes around the cat and check it for you.

Thomas.

 

I'm looking at your sig and trying to find out why you would be running rich. Do you have a cam? You also say it clears up at higher RPMs, that is not like a clogged cat. It would normally get worse as revs climbed.

Have you looked at the cat while the car was running? If a cat is clogged up enough to rob significant power it will be nearly glowing red hot. Take a peek under the car at night. If the front half of the cat is glowing, it's cloged for sure.