catalytic converter

I believe that im having catalytic converter issues, i think its breaking apart inside, and rattling around, as i hear it rattle, and heat shields are not loose, so its inside, also seem to be having some power issues, possibly caused by partial blockage of exhaust system.

due to a repair cost of around 500$, that i currently dont have to spend, what would happen if i clean out all the crap that is loose inside the cat, would the lack of a cat cause any issues with the engine, or is it purely environmental?

Why is it a $500 repair? GEt a new cat off Ebay for $50, cut the old one out and bolt up the new one. Or you can have a shop or buddy weld it in.

If it's an OBD-2 vehicle, you'll have problems, as there is an oxygen sensor before and after the conveter.

I bought a direct bolt in converter, unbolted the old one, bolted in the new one. Cost $150. Plus some beer.

I don't think the problems will be thier on OBD2 if you do it right. My friend hollowed his out on his 97 sonoma and there is no code their.HE has 4 O2 sensors//Just a thought

I thought if the ECM saw a difference in O2 levels between the sensors that it would throw a code. Never tried it myself. Maybe I assumed incorrectly.

you should (on obdII) get a rich code at the post cat o2 (it doesnt say rich, it says 'cat effishincy failure' and this can make you run lean

you should (on obdII) get a rich code at the post cat o2 (it doesnt say rich, it says 'cat effishincy failure' and this can make you run lean
Well thats what i thought but after he did it there was no code. Go figure.

Are you having a power loss at highway speeds or from the get go?
From what I was told is that you would see high speed torque loss.

Either way I havent had a Cat for several months. The only time I have seen the check engine light is when I first turn on the key.

I noticed a huge difference in the sound and of course she breaths a little eaiser without the cherry red 100 pounder hanging under the passengers seat.

aftermarket cats can set a code to for not being good enough

True/ Should check to see what max engine size is on it.

Are you having a power loss at highway speeds or from the get go?
From what I was told is that you would see high speed torque loss.



That's the problem I'm having right now.
I' replaced all the sensors, wires, plugs, fuel pump/filter.
And it takes me 30 seconds to get up to 55 right from the get go
in the morning. And warming up, it takes nearly 15 seconds
to get up there. I haven't a clue. If my mechanic can't figure it
out after coding and replacing, how am I?

My mechanic replaced my engine early last year, and all of the
maintenance I've had since. They're good. But I
am getting really concerned. The codes aren't getting me
piece of mind.

I would find someone willing to put a pipe in its place.
Just make sure they leave the part of the cat pipe where the o2 sensor threads in. They can just weld in front of it.

If it doesnt fix the problem no loss. If it creates more problems, just weld it back on. If nothing else your 1/4 mile time will be a 10th faster :) without it.

that will throw a light and lean the moter out

that will throw a light and lean the moter out
Mine does not.

what year is yours? if its obdI it wont

1995

95 has an obdI or a mix of I and II that doesn't have a post cat o2 sencer, you can cut the cat off anything without a post cat o2, but as of 96 it was manditory on all vehicals

I do have a sensor after the cat. Thats how I knew to tell him to leave that part of the pipe attached.

Mine works fine without the cat. And I still have an O2 sensor after the non cat.

being its not a full obdII is the reason you are not setting the code, that with some pure, 100% raw luck, anything 96 or newer needs an 02 cheater on the post cat o2 to keep the light off and the computer happy

actually i was thinking about takin the cat off, banging all the stuff out of it, and puttin it back on, total cost, $0 lol

Whats up dude ,
I have a 2001 blazer with 4.3 and lots of add on gadgets.
I also experienced the cat problem after i removed and replaced with pipe and flow master muff.It has been six months and i am now starting to have problems . I guess that was a dumb thing to do on my part .What would be the best thing to do now just put a stock converter back on . I would lose my deep and rich sound but she is a little to noisy to be honest.

get a GOOD aftermarket high flow cat, or an oe one

If you live in a state without emissions inspection, a bypass pipe can be installed. If not, beware of aftermarket converters. Some are smaller than the original factory converters and do not last as long. Yes, the original factory converter costs about $443.00 plus another $110.00 labor if the dealership does the work, but if you are planning on keeping your Blazer, consider it an investment.

I have a 98 4.3 4x4, and I am currently showing an o2 code...from what I have read from above...if I were to replace the cat with a pipe with the o2 sensor threaded into the pipe...it would run rich? Is my understanding correct? and what would happen if I use an o2 dummy? how would that keep it from running rich or lean?
Also I dont like the Idea of a hollow cat due to the fact that gas may accumulate in it. I would love to get rid of the cat anyways...any suggestions would be greatly appreciated.

i also own a 98, why pay for it, there is a recall on the cats from 98

Isn't the recall limited to 80,000 miles or less? That'd be great if you only drive 10,000 miles a year....

i also own a 98, why pay for it, there is a recall on the cats from 98
I currently have 155000 miles on my blazer, were can I look at the recall?
Is it on the web?

The EPA mandates that any 1995 or newer vehicle must carry a warranty through 80,000 miles. I seriously doubt that GM will do anything for you with almost double that on your converter.

Also, I don't think there is an official recall, but rather just a letter that was sent out reminding people of the warranty due to the guts of the converter breaking loose from the inside of the cat and causing a rattle.

Chrysler sent out a similar letter regarding 1999 pickups for what they called a "internal delamination of the converter" or something to that effect. Again, it would be replaced free if less than 80,000 miles.

Again though, there probably aren't too many 1998 vehicles on the road with 80K or less on the clock.

yes, biv, you are correct, it isn't a recall, because recalls are safty issues the factory is forced to change because they realy messed up... and im not sure on how long the forced warrenty is, i picked up an aftermarket high flow one...

you should (on obdII) get a rich code at the post cat o2 (it doesnt say rich, it says 'cat effishincy failure' and this can make you run leanWhats up fellows? I am experiencing the same problems on my 2000 blazer . Back about 6 months ago i removed my cat converter and stock muff . Replaced the muffler with a flow master and the cat convt well
just a piece of stainless pipe. No problem till now . service engine light comes on and it runs poorly now . I have all the after market performance upgrades to. So believe me i no when it is sick . It was a strong running blazer. Any suggestions on what to do and the cheapest way to go .:disappoin :disappoin

Originally Posted by dmbrisket 51
you should (on obdII) get a rich code at the post cat o2 (it doesnt say rich, it says 'cat effishincy failure' and this can make you run lean

Ok...my question is, why would it take 6 months for this to pop up? and I know there is a way around it. Any suggestions?

Check out www.o2simulator.com

well, i replaced my cat and it runs better now, but its still has nowhere near the power that my 4.0 ford ranger had, and this is a 4.3 vortech, im even more convinced now than ever that chevy sucks.

Check out www.o2simulator.com
so what you are saying is that if I use the o2simulator my engine will not start running lean 6 months from now? If this is the case im going with that option.

well, i replaced my cat and it runs better now, but its still has nowhere near the power that my 4.0 ford ranger had, and this is a 4.3 vortech, im even more convinced now than ever that chevy sucks.
Ill bet that if you perform the same things on a ford it will start doing similar things.....I dont nock any other american auto manufactures anymore...its the foreign makers we need to worry about.

Ill bet that if you perform the same things on a ford it will start doing similar things.....I dont nock any other american auto manufactures anymore...its the foreign makers we need to worry about.


i didnt do anything to either vehicle, but both at stock running condition, the 4.0 ford has way better acceleration and power than the 4.3 vortech, was all i was trying to say.

so what you are saying is that if I use the o2simulator my engine will not start running lean 6 months from now? If this is the case im going with that option.I cut mine off or had it removed last summer like in july . No problems at all.Drove to panama city that month my gas mileage was good I suppose. I dont know if the cool air this winter had a drastic change on it or what.I live in east TN so the air would be cooler, so does that mean it would run richer:banghead:

actually i was thinking about takin the cat off, banging all the stuff out of it, and puttin it back on, total cost, $0 lol

You are being cheap and the OBDII computer will hand you your butt by throwing a code.

Get a 2.25" cat off of ebay and have a shop install it for $100.

You can't just hollow it out and think the computer will not know.

i didnt do anything to either vehicle, but both at stock running condition, the 4.0 ford has way better acceleration and power than the 4.3 vortech, was all i was trying to say.

oh...ohtay.....

Just a note: if you hollow out your cat, you are creating a collection box for raw fuel. Not a good situation to be in if your engine decides to backfire.
although its unlikey to backfire I still dont like the idea of raw gas sitting in my exhaust system.