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beretta

Help with Chevy Catalytic Converter

12 posts in this topic

Hey guys, I need a little advice. I have a '97 chevy silverado 1500 with about 133,000 miles on it. Unfortuatly being in school I just cant buy a new or newer used one....so I have to try to figure something out. My service engine soon light is one and according to the dealer its because of the catalytic converter is plugged or bad or both. It runs alright as of right now but the dealer said at some point (quite possibly not to far off) it will begin running poorly and then not at all... I would rather fix the issue before it really becomes a problem and I would also like to get the SES light off thinking ahead to selling it.

My question is, Does anyone know how to replace or unplug one of these? Is there anyone who has done it?

Any suggestions? Thanks guys, I really appreciate it!

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For starters what code was set?

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If it was plugged you'd smell rotten eggs and have a major power loss.

Cut it off and weld in a straight pipe baby!

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I dont know the exact code (I could find out tomorrow) and I do not smell rotten eggs (unless I have chili). Power seems fine. I know its not completly blocked I thought just partially? Im 99% sure thats what the mechanic said it was though.

UJ-Gosh Id like to weld on a straight pipe but what happens when I want to sell it next fall? I know I would get docked on a trade in...i dont know how much though

One more question...what would happen if I disconnected it before the cat.? Any negatives?

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I found an old service order. It says "several codes found P131, 137,151,157 and P0300. I had an oxygen sensor replaced as well if that helps. Thanks again

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Quote:

One more question...what would happen if I disconnected it before the cat.? Any negatives?


I believe it is illegal in the state of minnesota to not have a catalytic converter connected.

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it is illegal to cut a cat out in MN, if not the whole nation. With a plugged cat, your computer will more than likely pop a bunch of codes, just as you have described. What happens is the sensors will relay bad information that is directly related to an indirect problem. Until the root cause is found, you could throw needless parts at a problem by just replacing each "faulty" component. Most of the time, the codes will pretty much point to one problem when interpreted by a skilled technician. One thing that happens in that model year, though, is the harness to the O2 sensors can become corroded and send a bad message to the computer as to what is going on, and in turn flag a bunch of DTC's (diagnostic trouble codes) when in fact the sensors may or may not be bad. Like I said, a skilled tech would get to the root. Hope this helps. I will try to remember to check the code #'s tomorrow at work and report back.

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I just went throught this this week on a 2002 Suburban with 116k on it. It was skipping cylinders. First the oxygen sensor was changed which resulted in a temporary small improvement. Then it got worse. I couldn't get above 55 MPH and had no power. It was only running on 5 cylinders. A new catalytic converter was put in yesterday and now it runs great. The shop I went to found one for around $450, plus labor. I don't know if that was good or not, but I needed the truck back ASAP. By the sounds of it, you have the same problem. Call around and get some bids if you can't do it yourself. Cars are money pits. I was going to use the money I spent on the truck for a new Vantage for my boat. mad.gif

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Quote:

.

Cut it off and weld in a straight pipe baby!


That would be the last thing you would want to do.

You don't have to have the rotten egg smell for it to be bad if it bad it's probably broke off inside of the converter you could bang on it with a rubber mallot or piece of wood to see if its rattling.

The code set would very helpfull.

Who checked it for you?

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beretta,

My first thought is "D.P.F.E." or "EGR valve". You probably are getting a catalytic deficiency code. If cat converter is plugged, car or truck will not have power or even run (as stated above). I would not rule out cutting out and putting in after market "cheap" cat or putting in straight pipe. I put in straight pipe system all the time for people who have new mustangs and other high performance cars. Even new diesel trucks. Exhaust shops all over do it all the time. Emissions was dropped years ago, the only thing to worry about is fuel economy and getting a loud exhaust ticket. The only entity that has to worry about having a "Catalytic Converter" on a car is manufacture, that or someone under the federal 8/80 emission’s warranty (to get coverage). When I remove cat converter, I do a little reprogramming in pcm and put elec. “U” plugs in o-2 sensor connector’s. You do not have to do this if you do not care about "check eng." light being on. Another alterative is to poor a cleaner down exhaust and let sit in cat for awhile. This would require removing exhaust from exhaust manifold. The old, old school trick is waiting until it starts lacking power, get eng warmed up (then shut off) and raise up on hoist or jack stands. After doing this spend around 10 minutes pounding the heck out of Catalytic converter with heavy duty hammer “BFH”. Try not to put a hole in it or knock off EGR tube. Once this is done, restart eng. And right away hold throttle to the boards. All the black carbon will shoot out tail pipe. Make sure you are outside during this repair attempt. 9 times out of 10 this will get you by. It works on a mid 80’s for many years.

Good Luck,

SHACKBASH

P.S.

Restricted or failed catalytic converters will not “always” exhibit a rotten egg smell. This is caused by sulfur amount in fuels, which could lead to catalytic failure. Usually a failure in the “EGR” system will cause a rotten egg smell. Some times if egr tube end is plugged in cat converter, you will get the smell.

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Like stated above, usually there is a root concern that started a cat converter to plug up. This could be for example a leaking intake manifold gasket. This would cause a lean code. When P.C.M. see's a lean code, it start to dump more fuel into eng. "richens fuel mixture" to prevent a lean cly. failure. This is a cool thing you car's computer does to save the eng., but the down side is the catalytic converter gets too much unburnt fumes and egr system and can not reburn up all of it (send it back to eng. for reburning). End result is a they build up in catalytic converter and form carbon. Catalytic converter basically burns the exhaust to lower hydro carbons levels to federal standards. Good Luck!

p.s

The catalytic converter is kind of like your colin. You do feed it right, it backs up.

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This thread will be locked until I can confirm and post federal and state emissions laws. I do believe that some advice and practices that have been recommended are unethical, enviromantally unsound and against the law. Once I have all the facts straight I will post them and reopen the post for further advice and or comments.

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