My cat started rattling today. Crawled under it and smacked it with a gloved fist, and sure enough, its the cat. I replaced the cat once at about 100k miles. Did the hughes plate at about 150k. Now at 170k I need a new cat. Makes me second guess my plenum repair. I know I did everything right, but I didn't like the looks of the plenum gasket I used. It was all steel, victor reinz brand, and its all I had on hand or I may have opted for the fel pro. Truck was torn apart, I had the one day off, so I used what came with the hughes order.

I did take the tb off and have a look at about 160k. Some oil in the very back, not enough to say pooling. More like...half a teaspoon maybe. Truck runs good, idles good. Goes through about 1 qt every oil change.

I suppose I will get the cat replaced with the magnaflow one. Supposedly the plenum leaking will clog the cat. If I look inside the old cat when I replace it, should I be able to see some sort of residue in there if a leaking plenum caused it to go bad? Sounds like the material in the cat is still intact, but seperated from the interior walls of the cat. I'm trying to decide if I want to re-replace the plenum gasket agan or just replace the cat. I don't want to ruin the new cat, but I don't want to do the plenum job again for no reason. As good as the truck is running, I'm leaning towards not redoing the gasket again. Anyone have any advice or opinions? Gut the cat and screw it? Lol.

 

I'm not sure if the plenum needs doin again, guessing that there is some residue might have a slight leak? I think the cat rattling is kinda common tho, it dosent mean its toast as far as im aware. I fixed my plenum at 160k and my cat clogged at 190k, so if the cat is bad now doesn't necessarily mean the plenum is bad. I replaced my cat with a magnaflow one, $60 on ebay new, i think it was a good investment

 

Another consideration is the type of muffler you are using. The popping and what not which comes from a non baffled muffler is supposed to reduce the lifespan of cats according to the guy who did my muffler. Apparently the pops are unburnt fuel explosions happening in the cat. I'm not exactly sure why but baffled mufflers are supposed to help prevent the cat damaging pops.

 

Thats why I don't use mufflers

 

Well, I did put a magnaflow, non baffled muffler on last winter. Maybe it killed my cat. Meee-ow

 

Notice any more power with the magnaflow cat? Was the truck louder? Just curious. I suppose I'll get one, don't want to let the old one get too bad and crack a head or something.

 

I can't really say if I gained any power, while i was waiting for my new cat to come i was runnin around cat free, which is almost tooo loud even for me lol (couldn't hear the radio) but the magnaflow is loader than the stock one for sure, it has a real nice tone to it i think. I do know the openings are bigger on the magnaflow compared to stock and the catalyst stuff in there isnt near as long so it is for sure less restrictive. Hope this helps!

 

Went to the only exhaust guy I've dealt with in the past today. He wanted 240 dollars for an installed catco cat. He says he stopped using magnaflows because he had too many complaints with cel's. I told him I'd get back with him, but I lied lol. Not spending that much on a cat. So I've got two questions:

1. Anyone have any trouble with cel's on an OBD II ram with a magnaflow cat?

2. Anyone have any luck getting the CEL off with the sparkplug nonfouler trick on an OBD II ram?

This has probably been discussed before, but searching through a lot of threads on a blackberry is a pain...

Just let me get a few "no cat, no cel" or "magnaflow cat for 2 yrs, no cel" responses, or vice versa, please.

 

Many folks have used the magnaflow cats, some have had CEL's, 99.99% of those were solved with the non-fouler trick, the others had a failed cat.

 

My cat is junk. Sounds like the motor is knocking sometimes, except the noise is coming out from under the truck.