Stoichiometric

iTrader: (10)

If you suspect that the cats are dead, I would either take the truck in for a new set or gut the ones you have now and forget about it. 10:1 is washing your cylinders rich which may have bad effects on your rings besides melting the cats and fouling spark plugs.

If you have aftermarket cats, they may not light off well all the time depending on how far downstream they are. They probably do their job when there is a load on the engine, but cool off at idle and the exhaust stinks.

2004SSS

iTrader: (25)

the first pic was my cat and im extremely lucky i found it because i didn thave a clue and it wasnt making noice or smelling funkily. so now they are gone and no worries about bad cats. i didnt run it rich for long but i guess it happens sometimes.

1SlowHoe

iTrader: (28)

Hmm, now you guys got me worried. After my LT install one of the O2 wires was touching the header and sent it into super rich mode unless I was in open loop. As soon as I gave it enough gas to go to OL it ran great but at idle and slow speeds it was pouring black smoke like a diesel on steroids. Only lasted about 10 miles on and off. I would have to cut the cats off to inspect them. So what should my rear O2s read to be normal @ cruise so I can not worry about this.

850mv?
870mv?
920mv?

By the way this happened in July and it still seems fine.

James B.

iTrader: (1)

Not rich but the fumes will burn your eyes and smell.

03sierraslt

iTrader: (22)

Well I have a infared thermometer and can check cat temp before and after. I would think by doing this it would tell you if they are acting as a big restriction however I dont know what a acceptable temp change should be.

litreddevil

iTrader: (4)

i blew 3 motors in my truck from a converter being cloged.it was melted.but their is times when i worked at the dealer ship truck would come in with the converter broken all up and would be all the way in the muffler and sometimes coming out the tail pipe

Kingpimp

iTrader: (1)

How would a clogged cat destroy a motor?

mwalls54

too much heat build up.

TURBHOE

iTrader: (4)

just gut them already. you've been wanting to do it since you bought the damn thing. lol if it gets alittle loud put on another magnaflow.

Snake Eater

Damn bolts are frozen on there. I tried heat and broke 2 extentions. They look clean and unrusted. WTF. I sprayed them and will try it again after some beer.