yes its very possible its bad cats, but a simple exhaust leak or a overly rich fuel/air ratio, or a badly timed ignition can also cause that symptom, Id suggest a complete tune up and verifying the trouble codes and checking the exhaust back pressure levels, and use of a vacuum gauge, and a compression check, reading the plugs for indications of a bad injector , etc. before you go swapping parts

 

the other thing i noticed is the truck runs at 150/ 160 dgrees. im pretty sure it is suposed to be at 180 to 210, for emissions purposes... also, i changed cap rotor plugs wires, plugs had alot of build up on them they were the original ones.... and there is no check engine light.... the truck has alot of power and runs smooth i dont think its an injector problem , i ran trans fluid into a vaccume line to make the exhaust smoke... there was no leaks at all.... the only symptom now is excesive exhaust smell in the cab when i run the heat... my feeling is its the cat... ive just never messed with a bad cat unless its smelled like rotten eggs... never had one that smelled like excesive exhaust


i also feel that having the plugs and wires as bad as they were caused the truck to run rich and wiped out the cat... this truck had no maintenance done to it except oil changes

 

:agree:

 

I have a 1997 Jimmy,just did a tune up in the fall....plugs,wires, cap & rotor......runs great.....havent had the problem like you though...I have owned my since day 1

simple regular maintence goes a long way :thumbsup:

 

i finnaly figured it out.. i drove the truck on sat for about 2 hours beating the piss out of it.. by the time i got back home the exhaust was stinking like rotten eggs,,, deff a bad cat... i digged deeper and found that the fuel spider is no good, over fueling and wipped the cat out

 

The fuel spider is a very common problem, as is the regulator on the spider.they like to leak gas. The oem set-up has injectors that connect to poppet valves w/ plastic tubing, crappy design. I've installed a replacement (upgraded) that has the injectors right at the ends, eliminating the poppet valves. I think Standard (they make tune up parts) is the co. that make it. This is a bizarre efi system.

 

yea i bought that type and installed it into my truck last saturday, i picked up about 2 miles to a gallon more now too, when you had problems with it did you have catt issues too

 

I work at a shop, so I've changed a couple of those each year. I guess if you drove it a while w/ a bad spider, the cat could go bad. Try hitting the cat, listen for loose material in it.

 

its not rattleing just smelling bad, i know its bad i just like varification.... it had a bad spider for an estimated 30,000 miles and sparkplugs where original truck has 85000 miles on it, and it was running at 150 degrees wrong thermostat ... between the three .... bye bye cat ... thanks for repliying

 

Hello all!!!!!!!! Thanks a lot for this great and very beneficial information for me. I really appreciate your conversation. This is very informative.



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