Catalytic converter change fixed my problems

I just wanted to relay my latest experience in case anyone is having a similar problem. About three months ago my check engine light (CEL) came on while driving down the road. I had it checked at Autozone and they gave me P0444. See this thread for more on that: http://www.automotiveforums.com/vbulletin/showthread.php?t=399169. They told me that it was the gas cap (it wasn't, that is usually P0440). The light went out on my way home, and I dismissed it, thinking that I would check on it later.

Since then, my car had been sort of losing power on the interstate and running rough at idle. About two or three weeks ago the check engine light came on. I went to Autozone and they pulled two occurances of code P0440 (the "gas cap" code). I pushed, prodded, and pulled at the EVAP stuff to try to hear a leak, but couldn't. I resolved to buy a new cap as the cheapest and most likely fix.

Yesterday, on my way to work, I drove about 20 miles (about 5 through many stoplights and in-town driving) and everything was fine. It was when I got to the tollbooth that I had a problem. As I was coming out of the toll lane, there was a sensation like the tranny was slipping. I had to really give it the revs to get going. This was wierd, because the tranny went in my '96 3.1L Lumina, but did not go this suddenly. It was a much more gradual failure.

I got off the next exit, stopped, and entering traffic it did it again. Like the car was bogging down, as if there were a severe governor on it. Getting back on the interstate northbound, same thing. BUT, when I got to the toll booth, it was fine.

Came home and by the time I got home, I was thinking about having read some of the posts on here, and tying that to the rough idle and CEL, I suspected that the cat could be at least part of the problem. After jumping on here and reading a few posts about it, and discovering that there was an 8 year, 80K mile warranty on the cat, I called the dealer.

Took it to them, and they confirmed that it was the catalytic converter. They changed it out no charge (74,996 miles on the car!) and it's back home today and running well.

If anyone has any issues like this they may do well to mention the cat to their mechanic or dealer.
Jim

Hmmm, maybe I've got the same problem with my Impala, an '02 LS (3.8L V-6). I do have a couple of troubleshooting questions though if you don't mind. First off, what mine does is like a real low audible rumble, almost the same noise as when your tires are out of balance and you're doing about 75mph only a little louder and always at the same pitch, meaning it doesn't matter what RPM's or speed I'm running, the noise is always the same. And it's a bad enough vibration to give double vision in the rear view mirror. Secondly, it feels like what you said about the transmission slipping slightly, but doing it a LOT. It stops when I let off the gas, and gets worse (louder) the more gas I apply. Also, it seems like it's worst before the car has a chance to warm up to operating temps. And lastly, it's getting worse over time*note*: it's been doing this gradually now for about a month.

At first I thought it was the tires because we had just had a new tire mounted because the previous one had a cut in the sidewall. I figured that they didn't balance it right, so I had them check it out and the tire was balanced perfectly. Then I got to thinking that it sounded like maybe a plug or plug wire or something in the fuel system wasn't working but a quick check didn't reveal anything out of the ordinary. So by this time I'm down to what appears to be my last option.....the tranny.....and I was PETRIFIED to find out how much a tranny for this car costs so I haven't found out yet. Then today as I'm getting ready to leave I decide to google my symptoms and here I am:)

This sounds almost exactly like the symptoms that my car is going through aside from the fact that I haven't had it hooked up to a scanner yet. I'm going to have it checked out and see what the damage is, surely it's not going to be as high as a transmission.... THANKS!!! :worshippy

*EDIT*---Oh yeah almost forgot, about how much did the cat. cost you including parts and labor? just curious...thanks again:D

I checked on a price for my converter and they quoted me 674 bucks installed. Thats crazy, i'm hesitant to put an after market one on it because i don't wanna stare at a service engine light. If anyone had good success with an aftermarket cat let me know. I'm in need of one...

thanks,
mike

Actually, mine didn't cost me a dime except for the gas that it took to get to the dealer. Because my car had less than 80K miles on it, the cat was still under warranty.
Jim

When i bought my 01 ls with 40k .The first week i called the dealer and told them to come get it because the tranny was gone(at least i was sure it was) it turned out to be the catilytic converter.

Well I checked around and the cheapest I've seen a cat for is about 150 bucks( check the link---- http://www.autopartswarehouse.com/cats/part.php?partid=3100&year=2002) . $675 = a HELL of a lot of labor cost for a pretty easy job if you have access to the right tools.
Putting it on myself won't be a problem aside from the fact that I don't have ready access to a wire feed welder and I completely suck at trying to weld exhaust with a regular rod welder.

"When i bought my 01 ls with 40k .The first week i called the dealer and told them to come get it because the tranny was gone(at least i was sure it was) it turned out to be the catilytic converter."

lol, tell me about it dude:) You have no idea how big of a 'tard I felt like after I realized what it actually was, especially considering how many times I've driven different vehicles with bad cats', you'd figure I'd remember what it felt/sounded like.....oh well, I'm glad I found this thread anyway because I was getting seriously worried about the tranny....thanks agian:)

Ya also at the time mine went when i was sure that it was the tranny i noticed that my tach was real erratic which made me think the tranny was slipping.When the dealer told me it was the cat converter i said i doubt it. But son of a bitch it was..

My '84 was not passing the emissions, the mechanic said that the cat was bad. It was hissing at the seams, which means it was plugged up. I went to my local NAPA dealer and bought one for like $115, they got me for a hose adapter kit for around $25 as well.

I chopped off all the bolts with an abrasive wheel, took like 10 minutes to get it off. The whole thing was done is less than an hour and made an immediate difference in how the car ran. It now passes the emissions with flying colors.

I've heard of problems with aftermarket cats, but this one worked for me.

Bob

my 84 impala had its old original small screen type converter on it, its the 229 v-6 with thm250c in it, well the converter was all that was left of the xhaust system, all the pipe after the converter was missing all way bacvk to what was left of the muffler right in front of the rear axle and what was left of the tailpipe, i yanked all that and the converter off real quick and installed a good used cheap muffler i had laying around about 2 1/4" inlet and wow its good to go now and is smooth and not very loud at all at least it doesnt sound like a retarded civic with bee buzz syndrome or anything like that lol

and this car is noticeably faster than my 88 caprice with LG4 305 engine,

the caprice is 2.56 axle and the impala is 2.73

hardly any difference and the caprice is 700r4 with 3.06 first but the impala with the taller first gear in the 250 tranny is STILL faster,.,..,

i like the impala better lol and its just an old beater million more miles on it than the caprice will probably ever get, and drives straighter too, isnt out of alignment and the brakes dont wobble either :D the old RWD 3.8L really is a good little engine, i had no idea! :DD





cat converter being plugged up can cause some real engine issues, for real, ive had to remove alot of them in the past, not just on old RWD cars but on the late 80s early 90s FWD cars too, have come across some REALLY plugged up ones!
i awlasy hack them off and clamp in a piece of straight pipe after having ends sized at muffler shop

dopnt tell them what you are doing with the piece of pipe though ! or they wont help you! just say you are working on a dirt track car or something really super old


good luck

there is a $50 cat at advance auto parts

So say I go and put an aftermarket cat on it. Say then the service engine light comes on as it does with some aftermarket cats. What is going on to trigger the light, is it hurting the motor, not enough pressure, to much gas. Whats going on to make the car trip the service engine soon light?

If it's not hurting the motor, i will just throw an after market one on there and get a simulator.

Let me know,
Mike

what causes the convertet to go out

Usually the male cat gets to be about 8 months old and starts spraying on the furniture.... oh not that type of CAT.

Some of the original cats had a plug where you could dump out the old pellets and put in fresh ones. But I never saw one that was actually serviced, people used to just bypass them with "test" pipes.

I'd say that old age is probably the biggest issue. The next would be an undesirable engine condition like an over-rich fuel mixture or stuck choke. But that should trip the check engine light and hopefullly most people would have it looked at.

The cat in my car was 20 years old, with 130k miles on it. I believe that they are only good for about 75-90k miles. The old clogged up ones are noticeably heavier than a fresh one.

Bob

On my wife's 2001 Impala LS, we found the CAT was clogged by running a vacuum test with a standard automotive vaccum gauge (0 - 30 in. hg). On the Series II 3800 you can tee into the fuel pressure regulator or purge solenoid vacuum lines. On the 3.4L, there are plenty of vaccum lines to tap into on the intake manifold. Normal vaccum in inches is around 15 or green area. To checked for a clogged CAT or excessive exhaust backpressure, you run the rpms up to around 2000 - 2500 and hold steady. Observe the gauge. If rpms drop towards zero or into yellow or red zones then there is a high probability its the CAT. Its a simple DIY test.

The CAT had what they call melt down and clogged. It was caused by a defective MAF sensor which was replaced first. Needless to say, we got it running fine in the end but the old lady decided to trade it in on a Nissan Maxima. Oh, well.