How difficult is it to replace Cat Converter

Ok, so I think my catalytic conver needs replacing. The heat shield is rattling pretty bad, and its pretty old and rusted and I have replaced or tuned-up just about everything else. So hopefully this will help my bogging down. Anyways I have called around to all the local shops (midas, mieneke, a few local) and the are looking for around $300 to replace it. But I can buy the part for around $100 so I am wondering where the $200 mark up comes from. I know labor and all but I can't imagine it would take a muffler expert very long to cut off and weld up a new one. It looks pretty straight forward just remove a few bolts and clamps and replace them. But I have found many projects to be a little more complicated than expected.

So how difficult would it be to do myself, and what surprise parts or tools should I pick up before attempting.

oh yeah, please don't post "Just cut it off, you don't need it" I know I can get by with out it. But I want everything in working oder in case I ever move, have to sell, ect.

Reply to
drallan
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It is a 89 s10 4.3 4x4 if that helps.

Reply to
drallan

Easy DIY job. Gaskets, manifold studs, PB blaster. I think I paid $150 delivered from

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Its been a few years, very happy with them.

Cheers

Reply to
Martin Riddle

Do I have to replace the manifolds back? or can I just remove the Cat?

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Reply to
drallan

Call and find out if the Y pipe is part of it. Most Y pipes are welded to the Cat. You'll need to back out the studs from the maifolds, since the nuts that mount the Y pipe on are probably toast by now.

Cheers

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Reply to
Martin Riddle

Rattling heat shields do not cause driveability problems.

AKA; swapnostics.

M'kay...

It comes from marking the parts up. It comes from maybe they don't source it from the same place where you price shopped.

Nope, probably not. That expertise is worth money.

Are the bolts rusted? Are the clamps rusted? Do you have an O/A torch? How big is your MIG welder? Ever tried welding the top side of an exhaust pipe where there is no room to see and no room for the MIG nozzle? Are you adept at reacting instantly when your weld hits a thin spot and avoid making a small burn hole a BIG burn hole. Are you fond of the taste of rust? Are you able to not flinch even a little bit when a MIG Bee-Bee burns your neck. How about when 20 of them hit you in 3 seconds. Can you weld blind?

Things you might find necessary; O/A torch Air chisel and appropriate pipe cutting bits (chisels). Whizzer (air powered cut off wheel) Saws-all Chain type pipe cutter. Hydraulic pipe expander MIG or gas welding equipment. Fire extinguisher (CO2 preferred)

Reply to
aarcuda69062

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what he said.....ditto

I managed a Mieneke....among others.

~:~ MarshMonster ~sips his coffee.....pours in some crownroyal~ ~:~

Reply to
Marsh Monster

Add a lift or at least 4 GOOD jack stands that can get the vehicle up enough so you can work under it.

Reply to
Steve W.

Hell, Steve, having had the exhuast pipe disconnect from the muffler end on a 1985 Fleetwood Brougham, and being out on the road not being able to lift the car to get the pipe free from the rear axle, and having had to use a hacksaw to cut through that very healthy portion of exhaust pipe just so I could get home without dealing with the nightmare of a pothole sending exhuast pipe up into my gas tank, I'd say $300 for a pro to do the job is a reasonable price indeed.

BTW, right after that ordeal, I did go out and buy a pipe cutter, which I DID use when replacing the catalytic converter on my 1976 Matador. I can honestly say that NO set of jack stands will raise a car enough to make any exhuast work convenient or comfortable. It can only be made that way on a whole car lift. I can also attest to the fact that rust, road dirt, grease, and animal entrails (we have a lot of roadkill here) make for an unpleasant after-lunch snack...

Oh... the pipe cutter works great on metal fence posts, by the way, so it's not like I'll NEVER use it again...

Reply to
Raymond Sirois

Alright, before I offend anymore muffler experts. I know the rattling heat shield does not cause performance problems. I have been working on diagnosing my problem and have narrowed it down to a few options now. I feel the cat may be clogged. Yes I know I need to go to a shop and have them test for back pressure before I just go and replace parts. I was at the auto parts store getting stuff for a tune up and asked for a quote on a cat, and to take a look at one. They did not have a direct fit replacement, but the universal one I looked at, looked pretty simple to replace. It was simply a small cat with heat shield installed, with an inlet and outlet pipe.

Is it not possible to just cut out the old cat and get some fittings, clamps, and maybe a little extra pipe and fit it back in? If the y pipe and all other pipes are in good shape then I don't understand why I can't do this. It may not look as pretty under the truck or may not be stock oem but as long as it works, is safe, and gets the job done I should be good.

I am very impressed that some of you know every tool and step in this process that a muffler shop would use. If all it takes is a little work to get the old stuff off, then I do not mind putting in an afternoon to save myself a few hundred. I understand that I am paying for expertise and all that at a shop. But if it is something that can be done at home I don't see why I should pay someone else to do it.

Reply to
drallan

Why not have them get the direct fit cat?

It's your truck, you can cut and cobble all you want. Question; when it's time to replace the exhaust pipe behind the cat, are you really happy with cutting the flange off of a brand new pipe in order to make it fit your previously installed one size fits all cat?

If all it takes is even less work to verify whether the cat is restricted, why wouldn't you do that instead of just throwing parts at it?

Cars and trucks rarely if ever respond the way a pissed off wife or girlfriend do, i.e., they seldom improve their behavior the more money and gifts you lavish on them.

It is against federal law to remove a functioning catalytic convertor from any vehicle originally equipped with one no matter what the reason. What valid reason do you have if you're not even willing to test the thing to see if it's restricted?

Reply to
aarcuda69062

I never said wasn't going to have it tested. All I have been interested in is how feasible the project would be to do by myself. I wanted to know my options so when I take it to the shop and if they say it is clogged I can make an educated decision on whether or not to have them replace it for me.

As to not getting the direct fit cat, If the direct fit involves more work ie, removing the manifold, fighting with rusty bolts, welding, and the universal just involved cutting and clamping and they both work the same, I don't see the need for the extra work other than to keep it looking cleaner under the truck. When the muffler needs replacing, later down the road (the one on it is only a year old) I don't mind cutting a flange to fit into a coupling as long as it works, Or just remove the clamp from the rear of the cat and attach the new pipe.

Look, I'm not trying to start and argument or compare who knows more and is a better expert. All I wanted to know was how difficult a job replacing the cat myself would be. It is an almost 20 year old work truck that I plan on driving into the ground. Honestly if I can patch in a cat while it may be ugly, if it fixes the problem, is safe and legal, then I don't really care how it looks. I am no expert but fitting pipes doesn't seem to be rocket science, it is in a straight section of the exhaust and if it is simply cut out, attach a coupling to the pipes, and clamp on the the new cat I don't see the prob. However say, that the clamps don't really hold or there was another reason as to why that would not work. A simple, No, I wouldn't recommend it because there is a lot more involved than it appears, is all that was necessary.

Reply to
drallan

You never said you were either. You make opening claims of performing diagnosis yet all you've done so far is shotgun unneeded parts at this thing.

Feasible is as far away as sliding under the truck and looking, where you'll find a 2 1/2" pipe which is the cat inlet slipped over the outlet of the Y pipe. At the back of the cat, you'll see a 2 7/8" ball coupling held together with a few bolts.

You don't have any options if the cat is plugged. If it's plugged, you need a new one.

Again, slide your ass under the truck, it will be obvious once you look at the exhaust lay out. Universal cats are never easier to install. Never.

I never mentioned the muffler, I could care less about your muffler. The part you're so intent on butchering is the exhaust pipe ahead of the muffler, once butchered, any subsequent exhaust work becomes an absolute miserable chore. You want to cut the front flange off of the exhaust pipe to use the universal cat, the exhaust pipe is now shorter meaning you'll need a cobble job patch to make it long enough, you've now also substituted bolt together flange fittings for slip together joints, slip together joints never ever come apart easily once they're clamped. Again, go under the truck and look at what you will be working on.

I could care less if you want to argue or not. Like I said, it's your truck, f*ck it up as you see fit.

Well, you wanted to know more than just that. Tell me; how are total strangers supposed to know what your capabilities are and what you might find difficult?

Or having it kill you.

So why haven't you bothered to look at the installation to see that what you're intent on doing is making much more work for yourself and leaving bigger possibilities for exhaust leaks, the system coming loose and becoming a total bitch to salvage when other parts need replacing?

It's not rocket science, but steel pipe doesn't stretch like a pair of underwear, so you'd better have a plan when the square peg doesn't fit in the round hole or you find yourself with a

1/4" gap between the two round holes.

A direct fit cat will be extremely easy to install (would be to me) as long as you have a way to slice the inlet pipe of the old cat open. The rest is just a few nuts and bolts. There is a reason GM designed it the way they did and it would be foolish to not take advantage of the way they designed it.

Reply to
aarcuda69062

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