clogged cats

[EAZY03MARAUDER]

I have the bottom 2 cats i belive they are clogged and the cone is broken in one of them ..how much effect does this have on my car for a power and performance.is their a way to fix without buying new ones or does any one have some old ones.Boy iam broke and this is not good :mad2::(:(

[ctrlraven]

If it's the rear cats you could just remove them and have a piece of pipe put in the place. Cheaper than replacing them, pick up a little more exhaust note and just a hair better performance.

[EAZY03MARAUDER]

if they are bad that would give it that missing sound i have no check engine light on and would that effect the take off and the power when iam flooring it oh and i can see the heat waves from one side and here that damn rattling from the other

[whitey]

I just removed mine last week. +1 on the sound. I used 2 /12 exhaust pipe and exhaust clamps, and 2 other fittings but you should be able to do it with 2 1/4 pipe. Use the flared end for the intake of the cat and cut the other end to size. Mine had a few leaks, but hi temp rtv sealant took care of it. Im not sure how long the sealant will hold up, it's rated for 650F....but with 2 1/4 pipe you might not even need it.

[ctrlraven]

I just removed mine last week. +1 on the sound. I used 2 /12 exhaust pipe and exhaust clamps, and 2 other fittings but you should be able to do it with 2 1/4 pipe. Use the flared end for the intake of the cat and cut the other end to size. Mine had a few leaks, but hi temp rtv sealant took care of it. Im not sure how long the sealant will hold up, it's rated for 650F....but with 2 1/4 pipe you might not even need it.

I would still have it all welded up to look cleaner, ensure there will be no future leaks and less noticeable to an emission tech with a mirror.

How do you like the exhaust note now?

[EAZY03MARAUDER]

so this would hurt my take off and performance...explain wht a DTR means only had my MM for month its an 03 but this cars has been sittin and the owner didnt take care of it but the motor runs like champ purrs like a kitten..finding out all the problems but i got it for less than 5 grand

[JBFTech]

Yes a clogged cat will hurt performance, and if not taken care of, will cause future problems. Just have the rears removed.

[88LTDCV351]

My first car was a 81 Ford Thunderbird. Started having trouble accelerating one day. Just would accelerate slowly. Then eventually I couldn't go above 40 miles an hour. Took it in to a shop and they said the cats were clogged. It was my first car so cats sounded expensive to me. Sold the car and saw someone driving it around a few times. Got a lemon after that and had wished I kept the T-bird but had better cars afterwards.

[whitey]

The exhaust sounds perfect to me...not obnoxiously loud, not quiet. To explain it better...for my car, NA with bolt ons, sounds perfect. Dooms car with that s/c, his exhaust sounds perfect. I dont feel like spending the $150 to have it welded, plus with the emmissions people...i can bullshat my way out of murder if i needed to;) being cheap aint easy.

[kingace]

DTR stands for Dark Toreador Red, type of paint used for the MM.

[sailsmen]

Hollow out the cats.

[Spectragod]

I dont feel like spending the $150 to have it welded, plus with the emmissions people...i can bullshat my way out of murder if i needed to;) being cheap aint easy.

Doesn't everyone have a welder in their garage???


Hollow out the cats.

Right here is a good suggestion, a little time and no $$$ involved.

[B.C. Bake]

Just wondering, does somebody sell an aftermarket kit that just bolts on to delete the rear cats? Thanks in advance.:rolleyes:

[ctrlraven]

$150? lol If the pipe is already in place, it might be $20-50 to have it welded.

[B.C. Bake]

OK just realized what I asked, You would have to weld on a flange after the fist set in order for this to work. I was thinking of customizing a set so you can interchange because of any emissions local or state problems, prolly more trouble than it's worth.:confused:

[myrodr]

loud2004 marquis has rear cat delete pipes for sale

[whitey]

True chris, if the sealant starts to leak i'll definitely look into it now that everything is in place it shouldn't cost too much. The last guy i talked to before i did it myself basically told me to GTFO, in a nicer way. Lol

[ctrlraven]

True chris, if the sealant starts to leak i'll definitely look into it now that everything is in place it shouldn't cost too much. The last guy i talked to before i did it myself basically told me to GTFO, in a nicer way. Lol
When I took mine out, my friend's welder quit half way through doing the delete. I ended up taking the car to Tony's Custom Exhaust in Glen Burnie, they finished the welding and rtv'ed up the flange. I really wish I had kept my stock downtubes to turn around and sell to someone if they wanted an easier way.

[Black Machine]

Will removing the rears cat throw a code?

[whitey]

No codes, there are no sensors after the second cats.

[fastblackmerc]

No codes, there are no sensors after the second cats.

Only if they are turned off in your tune.

[ctrlraven]

Only if they are turned off in your tune.
Doesn't matter stock tune or tuned, the rear O2 sensors are in front of the rear cats. The rear O2 sensors just babysit the front ones and ensure they are reading properly and the front cats are good.

I've removed two sets of rear cats for friends who own CVs, no codes after being removed and one went through state emissions testing two months ago with no problems.

[whitey]

I noticed last night that my tips are a little sootier/black than they used to get. It might just be that the sealants ive used are burning off on the inside, or that not having the 2nd cats on actually do make the exhaust alot dirtier. Just something i figure id point out, i'll wipe them off today any see if they it might have just been some sealant burning off.