Greetings from a newbie on the site. I am inquiring about an 02 RT (were there any 2wd RTs?), all stock. She failed her emissions test with 125K miles. The shop says it's time for a new cat. I don't know why but will as soon as the old one comes off. I have looked through a bunch of threads here and have come up with several 2006-7 discussions on the relative merits of replacing the stock cats or not.

I don't have a choice, I need to replace it and would prefer not to spend $600-$700 doing it. I can buy an aftermarket cat on fleabay for less than $100 (delivered) and have it installed for another $120. Does anyone have either good or bad experiences with aftermarket cats? Are there ones to stay away from? Is there a superior one?

Thanks for your help.

 

IIRC, no there is no such thing as a 2WD R/T, I believe they were only offered as AWD. As for aftermarket CATs, I'd recommend sticking with an OEM equivalent longer style CAT rather than a high-flow shorty CAT because these vehicles are known to not like the shorter CAT converters.

As far as superior ones, as long as it does it's job I don't see why one would be better than the next. I'd probably stick with a brand you've heard of just to make sure you don't have to worry about replacing it again in the near future.

 

yup as stated above by widow make sure you dont end up with a short one these trucks dont like those, the stock cat is a high flow cat so if you wanted to get a stocker (im sure thats alot more expensive than aftermarket) it would be a fine choice, otherwise any name brand should work just fine.

 

Thanks guys, I was tending to the shorter ones due to the simplified construction. I'll go with a traditional construction.

 

+1 No R/T's were made in 2WD, they are all 4X4 AWD's.

+3 Stick with OEM size and type. Don't forget to take your old one in for a nice recycling check!

 

Just a quick update. Finally decided on a Magnaflow, same cross-section as original but about 3" shorter. Waiting for delivery then off to the muffler shop.

 

OK, this is turning out to be a pain in the a$$. I got a new Magnaflow universal cat (#94106) off of fleabay. Took it to the local Midas who told me it would be $120 to install. Turned out to be $230, go figure . . .

Now for the fun part. Went to emissions today and the NOx is now UP to 3.4. It was only 2.6 with the old cat! I'm now into this to the tune of $350 and have taken .8 steps backwards! Besides being royally Pi$$3*, I am at a complete loss as to a possible cure. Any suggestions????

 

Well you did take a 3" shorter version and a high flow one to boot.


Now if it were me,

I would empty the tank and fill it with Super Premium Chevron gas, replace the oil and filter, change the spark plugs (cheap Champion Copper Plugs) gap at .040, maybe replace the pre-O2 sensor, Seafoam the motor, and take it to a different shop.

 

Thanks Hydra. I took off and replaced the plenum gasket (another $250) before seeing your last post. It was burning a quart in 1500 miles, so I'm thinking it needed that anyway. The NOx is back down to where it started. I have already changed the oil and filter. I'll try the Seafoam and new plugs and post the results. We don't have Chevron here so I'll try some the best gas I can get and add some octane booster.

I scanned the diagnostic charts and am going to post them in a new thread to see If one of you wizard types can explain what's going on with this car.

 

Some other things that can cause increased Nox are a bad or failing injector causing a cylinder to run lean (a simple check for these is to unplug and check the resistance with an ohm meter), burning oil will build up carbon in the combustion chamber that can cause detonation, if you have a habit of mixing tap water with your coolant it’ll cause scale to build up and can block water passages… Basically anything that causes combustion chambers to run hotter than normal will increase Nox emissions.