1994 Chevy Blazer s10 exhaust problems?

Question

Every 3 months, I replace my cat and muffler. The hydrocarbons keeps deterioting my cat and muffler. I have no clue what is causing this. My blazer has 197,000 miles. I've replaced the plugs and wires, with Bosch products. Replaced the EGR with an AC Delco. And still the same thing. My cat gets plugged up and doesn't accelerate well at all. The exhaust shop I go to, deny my warranties. I can only think of going straight pipe with my funds. This being my only vehicle. What causes this and should I go straight pipe before I junk this ride?

Answer 1

I actually saw this before. What it turned out to be was the fuel pressure regulator was leaking fuel into the plenum. It was just putting raw gas into the exhaust system. We removed the upper plenum, replace the leaking regulator, and put some AC spark plugs in it, and it was fine after that. The reason I used AC plugs is this. To get the best out of any vehicle, use the plugs that came in it. They do a lot of research and development on their vehicles, and if these are the plugs they decided was best for that particular vehicle, then I Guess they know what they are talking about, or else they would have used something else. I once saw a car that the tune up shop put a new set of plugs in, and it wouldn't hit a lick. We had to go get it with the tow truck from their shop. Even though these plugs were brand new, they wouldn't hit a lick! We installed a new set of plugs that was made for the car, and it fired up like nobodies business. You could be burning oil, but I would think you would see blue smoke. Gas makes black smoke, and will clog a cat when it has a lot that don't burn well. It also washes other stuff into the system such as oil and dirt.
Part 2: My wife has a "94" S-10 blazer with a 4.3 cpfi (central port fuel injection) Vortec engine. She purchased it new, and now has close to 250,000 miles on it. It still runs great, doesn't burn any oil, and the only major thing that I have done to it is put a timing chain & gear set in it. I have changed to oil on schedule and use Casterol 10w 30w in it. We run a bottle of STP injector cleaner (the black bottle) in it every 2 weeks. I have replaced the EGR valve 3 times since it was new, and replaced the fuel pressure regulator/poppet nozzle assembly once. I have replaced the fuel pump once, and keep the fuel filter changed every 6,000 miles. Outside of normal tune ups and regular things like hoses and belts, this vehicle runs like new. If this isn't proof a vehicle will go that far and still run good, then I don't know what is. By the way, the cat problem you are having is the problem she had a couple of years ago. I replaced the fuel pressure regulator/poppet nozzle assembly, and installed a new O2 sensor. This fixed the problem! How I found the problem was; I kept hearing something sloshing, and smelled gas all the time. There was a good two inches of gas inside the plenum, and it kept stopping up the cat and EGR valve. Go figure?
Glad to help you, Good Luck!!!

Answer 2

every 3 months you replace your exhaust!??!?! Theres no way this could be a choice of yours, because thats insane. What you need to do, is flush your engine. What you do is drain the oil completely, then replace it with a kerosene (aka, engine cleaner). light oil mixture, then start your car breifly, then shut it off, drain the kerosene, fill again with a light oil, run it for a bit longer, then finally fill it with whatever weight of oil you use. This will clean the carbon deposits.
Next, STOP USING CHEAP GAS.
I cant even imagine a circumstance that a cat and muffler would need to be replaced every 3 months. How much oil does your blazer burn a month? Is it a quart a day... an hour?
Thats insane, your muffler guy is screwing you big time. Take it somewhere else, and have them replace the cat with a straightpipe or high flow cat, that will solve the problem of it being clogged (if thats even possible after replacing it less then 3 months ago).
So you replaced the plugs and wires, did you replace the ignitor as well? If you have new plugs and wires but a bad ignitor, you havent accomplished anything.
While your at it, see if you have a fuel filter in place.I mean to clog a cat every 3 months, you must be burning garbage in your cylinders.
And after that, see if you have an air filter on the car!

Answer 3

Chevy Blazer Exhaust

Answer 4

Check the rest of the emissions system.Whats the o2 sensor doing?? How are the injectors??? A leaky injector will plug a cat in a couple of weeks.If its the engine with the plastic intake and the spider injector set up they are bad for poor injectors. Coolant temp sender will cause it to run rich if its not working right.Lots of things it could be still.Hope I helped and good luck.

GM tech for 20 years

Answer 5

I have a 2003 Blazer and having faulty O2 sensors made my catalytic converter go bad and had to replace all of the above. I was told that the O2 sensors dealt with the fuel mixture and how rich it was. It's best to check with a certified mechanic.

Answer 6

You're clogging the cat with tons of unburnt hydrocarbons. Quit pouring money into that worn out engine.

Answer 7

i would take the cat off and take the guts out of it and put it back as a decoy because it is the law u have 2 have one it would be like having a straight pipe

Answer 8

I had the exact same as musiclick, It was exactly as he done.And i had 2 fuel return lines leaking. It was heat rotting the two fuel lines under the plenium.

Answer 9

You are burning oil, and you can't use a cat.Bosch plugs don't work well. They produce a small spark. I use autolite plat. plugs.

Answer 10

Consuming a lot of oil it is shot.Don`t waste your money get something else