I need to find a replacement catalytic converter for my 03 ext. tb. I was having some overheating issues which lead back to a hole in the coolant loop (sucking air) after that problem was fixed I could not get the engine to rev over 1500 rpms. this lead to removing the o2 sensor for testing and I can now get up to speed without bogging down, so i am certain the cat is plugged. Im looking for a bolt on catalytic converter as I cant do the welding atm. is there a bolt on converter that people have had good success with? I am located in florida and we don't have any emissions to deal with. also so i dont prematurely wear out the new one should i be replacing/ testing anything else besides the t-stat?
SOLVED! replacement cat
- Thread starter jak03TB
- Start date
2003 CHEVROLET TRAILBLAZER 4.2L L6 Catalytic Converter | RockAuto
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I would also clean the throttle body.
Mooseman
Moderator
That's the thing with any aftermarket cat, they won't last as long as the original. Looking at those ones at RA, the Davico look more like the original casings, round and fully welded, while all the other brands all look like a universal cat was welded onto the pipes. And the pipes look better. Just an observation, not any experience.
just making sure i have everything i need, this would be the donut gasket for the inlet side.
is there a flat gasket needed on the outlet side? i cant seem to locate one on the exhaust diagram.
is there a flat gasket needed on the outlet side? i cant seem to locate one on the exhaust diagram.
Mooseman
Moderator
I don't remember one there. IIRC it's a ball and socket. If it needs one, it should be easy to find one locally.
JayArr
Member
Get the OEM doughnut gasket if you can. There is a reason the aftermarket one is so cheap.
I went through three of the aftermarket gaskets before I realized that the OEM quality is much much higher than the aftermarket.
The aftermarket ones tended to burn out in a year or so and then you have to do the job again.
I went through three of the aftermarket gaskets before I realized that the OEM quality is much much higher than the aftermarket.
The aftermarket ones tended to burn out in a year or so and then you have to do the job again.
aaserv
Member
I bought the Magnaflow complete set. Pipes from manifold to muffler. lil over $1000. Couldnt find a shop that would install them. They all said Magnaflow were cheap Chinese with a MF heat shield wrapped around them and wouldnt even pass state inspection brand new.. Ended up taking to a shop that tuned out the cats and it passed inspection yesterday.
thanks to everyone for the help and guidance. these are the products I went with:
I also wanted to clarify as this may help someone else who is doing a cat replacement. there is only a gasket on the inlet side. the outlet side just mates together. so don't bother searching for a product that you cant find and dont need. i had no issues with the install of the davico cat. the t-stat is functioning properly and everything seems to be running correctly. it feels so good to have her back on the road. at 212k miles i think the cat just gave up. i couldnt find any obvious reason for its failure. i will update if there is any issues with this brand cat.
I also wanted to clarify as this may help someone else who is doing a cat replacement. there is only a gasket on the inlet side. the outlet side just mates together. so don't bother searching for a product that you cant find and dont need. i had no issues with the install of the davico cat. the t-stat is functioning properly and everything seems to be running correctly. it feels so good to have her back on the road. at 212k miles i think the cat just gave up. i couldnt find any obvious reason for its failure. i will update if there is any issues with this brand cat.
JayArr
Member
has your cat been repaired before? mine had not been touched and was original from factory. it did not have one on the outlet side. i could not find any reference to a rear gasket anywhere either. im not saying im right, this is just what i found. i will try to dig through the haynes manual and see if it references it in there. if it is supposed to be there we should be able to locate a gm part #
JayArr
Member
Maybe my cat pipe was an aftermarket?
It was hard to get a good angle but I snapped some pics as I was putting it back together.
1) without the gasket
2) with the gasket
3) all tightened up
I believe without the gasket this joint would leak like a sieve on my car.
It was hard to get a good angle but I snapped some pics as I was putting it back together.
1) without the gasket
2) with the gasket
3) all tightened up
I believe without the gasket this joint would leak like a sieve on my car.
Attachments
Mooseman
Moderator
JayArr
Member
Here's what I don't get, look closely at picture, notice the expanded shoulder pointed at by the red arrow? It's at a depth that the short little steel bump pointed at by the blue arrow would never reach.
There are two steps before the pipe diameter. The steel "blue" bump reaches about halfway into the muffler pipe and fills the first "step" and the gasket fills the second step of the union.
It's been like this for years, more than 5, and it doesn't leak., I'm sure it would if I took the gasket out and not just because of rust.
Is this a difference between Base model and XL? Or just a bunch of aftermarket stuff the previous owner installed?
There are two steps before the pipe diameter. The steel "blue" bump reaches about halfway into the muffler pipe and fills the first "step" and the gasket fills the second step of the union.
It's been like this for years, more than 5, and it doesn't leak., I'm sure it would if I took the gasket out and not just because of rust.
Is this a difference between Base model and XL? Or just a bunch of aftermarket stuff the previous owner installed?
Attachments
here is a few things i think may help. this is a picture of my outlet pipe reinstalled. the shoulder of one end is just pressure fit against the other. there is a gap between the retaining brackets but with the shoulder going into the outlet pipe is a very snug fit.
the haynes manual was extremely vague and had no pictures of any merit. i was however able to find a few other pictures online, so it must be true...
this magnaflow kit says: Gasket Or Seal Included: Yes
there is only a gasket pictured for the inlet pipe.
there is also a diagram i found:
if you see there is a gasket and part number on the inlet side. on the outlet side it says (gasket NR)
i am ASSUMING the nr is not required or something similar because there is no icon or part number.
All of this being said if your outlet pipe leaks with out the gasket and doesn't leak with the gasket i don't see the harm in having one in there but maybe i'm wrong. i hope this helps.
*edit* as far as difference between swb and lwb, I think it is only the length of the pipe.
the haynes manual was extremely vague and had no pictures of any merit. i was however able to find a few other pictures online, so it must be true...
this magnaflow kit says: Gasket Or Seal Included: Yes
there is only a gasket pictured for the inlet pipe.
there is also a diagram i found:
if you see there is a gasket and part number on the inlet side. on the outlet side it says (gasket NR)
i am ASSUMING the nr is not required or something similar because there is no icon or part number.
All of this being said if your outlet pipe leaks with out the gasket and doesn't leak with the gasket i don't see the harm in having one in there but maybe i'm wrong. i hope this helps.
*edit* as far as difference between swb and lwb, I think it is only the length of the pipe.
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JayArr
Member
Do you think it's possible that the engineers designed the joint to accept a gasket and then later decided it wasn't necessary?
Next time I'm under there I'll remove the gasket and see if my hunch that it will leak is correct. Maybe I'm wrong and it won't leak and the gasket isn't necessary.
Next time I'm under there I'll remove the gasket and see if my hunch that it will leak is correct. Maybe I'm wrong and it won't leak and the gasket isn't necessary.
Mooseman
Moderator
