moosestang

Someone mentioned it being a common problem with FI. Has anyone actually clogged a cat?

Since I was driving on 7 cylinders for a few days, i'm going to remove my H pipe to visually inspect. Does anyone have a sound clip of their exhaust with gutted stock H pipe?

danzcool

FWIW I've never heard of anyone clogging the stock cats, but I have heard of a few clogging aftermarket "hi-flow" cats.

SpartaPerformance

I agree, clogging a factory cat is almost impossible. For the mixture to be that lean where you'd melt the substrate you'd have other issues then clogged cats.

BruceH

Boozehsey had a catastophic motor failure due to a clogged kooks cat. You would notice it though, his car was driving like crap and he kept doing wot pulls with his tuner trying to figure it out.

moosestang

I thought it was rich a/f or unburned fuel that killed them.

Anyone think I will run to lean by gutting the stock cats? There are sound clips on youtube with off road H and stock mufflers that sound pretty good. My car had a 10.8:1 a/f ratio when I had it dynoed a few years ago. I can't see the extra flow causing a substantially lean a/f mixture.

Simon1

Mine didn't change in the AF. It was really loud though.

I will be putting in a off road mid pipe this winter.

808muscle

Jim Jr at JDM told me it was a real good idea for me to cut out my HF ceramic cats as they would melt in less than 6 months with FI. I am having that done and placing some 12 inch cherry bomb mufflers to act as a resonator. My exhaust is very strange. It goes in this order.

Pypes Longtubes
H pipe
12" cherry bombs
pypes m80s
flowmaster American Thunder mufflers.

Cams, longtubes and FI equals one loud as car!!!

Diabolical!

Wow 808, do you happen to have a pic of the underside of your ride? It's got to look interesting.

06mach1

A misfire will possibly cause a rich condition in the cat. The cat inturn then burns the excess fuel causing the cat temperature to rise higher than normal which "melts" the internal parts of the cat. Driving with the MIL flashing will cause this issue.

Lifter583

I had my 08 GT500 blow the cats...I had recently upgraded the blower pulley and all that goes with it...was launching down a freeway on ramp at WOT when it looked like a chalk bag had just exploded behind the car...turned out it was ceramic particals and dust...pulled the cats off and they were falling apart...I bought the car with 558 miles on it and the guy mostly just idled around...I am sure it was running rich and burned the cats...