Embarrassed to ask...Cat Converter.

[DieselDavey]

Hi again...

I searched all over this and another site!

Do I need to change the exhaust system in order to get rid of the catalytic converter?

I don't weld, I'm broke (hours just got cut at work...) and I think the cat is plugged...

It's piped solid all the way from the down pipe to the cat...

Is there a way to cut out the cat, and install the so called "test pipe"?

Thanks!

Dave

[DmaxMaverick]

You can cut the pipe (squarely) at both ends of the cat. Leave at least 4" of clean pipe (whichever pipe you will be reusing). Make your "repair", then reinstall it with butt splice clamps. Or, install a section of pipe of the same size. I don't recall the brand or source for the clamps (I can find out later, if necessary). They are stainless steel sheet metal that is pulled together with 2 bolts. They make a perfect seal if installed properly. You must get the clamps of the same size as the pipe. They're not cheap, but work very will if you can't weld it. A muffler shop probably won't help you with your test, anyway (not legal for them).

[JCM5]

NAPA auto parts sells a 10 foot pc of 3" diameter for around $60
Then buy the connectors and 4 clamps.
use a saw to cut the cat off, should cost less then $100

Murrays Auto or Autozone types do not sell 3" pipes long enough

There is no bending required or additional supports needed for this.

[JTodd]

I cut mine off and spliced in a piece I got from an independent exhaust shop. I got a 4' piece expanded on one end for about $15. (I got rid of the muffler at the same time) I welded the hanger onto the section, but hardly need to as the weight of the straight pipe is much, much less than the weight of the cat and muffler combined.

[rhsub]

Cut the exhaust pipe as straight as possible either in front of or behind cat, which ever pipe is the straightest, behind the cat is best, drop the cat down and take a big bar and beat all of the inards out of the cat, if you cut behind the cat start the engine and rev it up to blow everything out, if you cut in front of cat take a shop vac and clean it out, make sure you get everything out so it doesn't plug the muffler, reattach pipe with a band type clamp, most large truck parts stores have them, they are common on big trucks
Good luck
Ron

[redbird2]

I would not knock the insides out there is a good scrap market for these CATs as you hear on the news all the time about dealerships and others having converters stolen, I know first hand we have lost at least 12 in the last year to his, shop around junk yards recyclers see who paying the most should pay for the pipe you need to put in.


I would go to local muffler shop have them make you pipe just like JTodd did, NAPA should be able to get you the band clamp

[bl78ljb]

Dave,
The first question I have for you is what is the vehicle this is in and what is the engine VIN code? If you have an F code engine you may be looking at a soot filter (which could be clogged as well) and not a kitty. The one that came off my Burb looked like a kitty and was welded onto the pipe, but is just the factory soot filter (gave me a bit of a scare when I got my new exhaust knowing I had an F code engine and didn't get a kitty and looked under the truck when I got it to the shop who then looked and reassured me it was not a kitty). So before you go to cutting and welding be sure you have to do this. If it is just the soot filter you should be able to burn it clean by running some hot for a bit.

[MarkMorissette]

I've had several cats completely removed (with a replacement pipe in it's place) for about $20 at a local exhaust shop. It takes about 10 minutes by a competent exhaust guy.

You need to find a shop where the guys are not afraid of a welder and custom pipe. A run of the mill place where it's a bunch of kids replacing parts with OEM replacements won't cut the mustard for what you need.

[DieselDavey]

Thanks again everyone,

I had to do some research to figure out what code engine I have...

Turns out its code "f" 1999 Suburban! No Cat! Right?

So... In other posts I've asked about low power when towing.

Vacuum to Waste Gate appears good (can not move waste gate lever when idling).

Lift Pump operation verified.

New air filter.

New fuel filter.

A clogged cat was the next step in figuring out what the problem is. Now I guess I can rule that out.

If what I thought was the Cat is a "Soot Trap", and that is clogged, maybe my trip to Canada pulling my camper will blow it out? I've towed the camper around 120 miles so far (30 miles per trip for a total of 120).

Any other ideas? Maybe I should start a new thread, or revisit the old thread regarding the power issue.

Dave

[DmaxMaverick]

Filters first showed up on GM Diesel pickups in 2007.5 (DPF = Diesel Particulate Filter). On earlier models, if it has a little muffler looking thing in front of the muffler, it has a cat. More affectionately referred to as a soot trap. Some of them were replaced with resonators. If you pull it out and look through it and it looks like a screen door, it's a catalytic converter. VIN code F engines came with a cat, if they came with anything at all. They get plugged up. Cleaning them by "blowing them out" with heavy use is very temporary. And......the EGT's required to "burn" out the soot is not good in the cylinders and turbo. It may help, but once they plug, it usually isn't long before someone needs to take out the cat. Replace it, modify it, or eliminate it. One or the other will need to be done.