Hello to all,

Bought a 2000 blazer 4x4 4.3 liter. drove fine for a month. Heater doesnt get hot, not too worried. Then the real issues started. One morning i decided to change all the filters. About two or three trips down the road all was good. I start my car and kapoot! car pops and smoke comes from the hood. Sounds like too much back pressure. I sit for a minute try and crank it. car turns over and finally turns on, revs to 4000 rpm and then sputters out. dang! open the hood try again. car starts and I put it in reverse and dash out. car is running like crap. I drive it in these conditions for 3 days. I knew i had a loose vac line but couldnt put a finger on it. I looked and listened and thought maybe when i pulled the air filter that something came loose. found the line and reconnected it. car started fine and idled at normal range. then about 2 days later i started getting a real foul smell like the cat was going out. I started my car and out of nowhere it popped... smoke came out and the vac line was off again!

I crawled under the car and noticed the cat is welded on the downpipe not bolted on as some diagrams show.

I need to go on a long trip out of town. 200 miles there and 200 back. is my car going to make it? can i cut the cat and drive it to the city to be fixed? i live in a small town so getting this cat fixed is gonna require me driving with it plugged or me to take it off.

what should i do? is this even the problem?

thanks for all your help, i know i can get honest input here

 

I would recommend you find the source of the problem. I doubt that the cat is the issue if it drives fine until the vacuum line pops off. Cats usually flow freely or are plugged up. Not a works today, gone tomorrow, back the next day type of thing.

And a loud pop then smoke is not typical for a vacuum line.

Do us a favor and take some pictures of the line you are talking about and provide more information about the problem in greater detail if you can.

 

i will take pictures. the car has very bad acceleration poor fuel economy and smells of rotten eggs like its running rich or something. it never did this til the vac line came loose. once i reconnected the line the car ran fine just smells horrible and the exhaust seems to be hotter. the car shakes and also takes forever to start. sometimes when i start the car it sounds like a boat motor out of water. at low rpms it makes a poot poot poot poot that turns into a popping sound. then eventually subsides. the car smells like fireworks or rotten eggs... so i just figured it was the cat. I thought it may have went out because the fuel ratio was so bad with a loose vac line.

give me time to get home and grab the camera. ill snap a few photos of the lines that pop off from the engine and release the smoke

 

Ok, the new details do sound like a failing cat. Initially, it sounded like it ran just fine up until the line came loose.

 

ok i figured... now do you think i should cut the cat or drive it with a plugged cat for 200 miles

 

I wouldn't recommend driving it like it is if the cat is plugged up. I would try and get it fixed properly before the drive.

 

I literally live 80 miles from the nearest trustowrthy shop. I took it to the local mechanic and all he did was tell me my injectors were plugged, my radiator was plugged my transmission was slipping all these issues that i know arent the problem. I know its illegal but can i drive it to the city with the cat cut out to be repaired? the service engine light is on.

also

will my driving it with the vac line off for those few days cause the o2 sensors to fail? what do you think caused the cat to fail? the bad fuel to air ratio or something?

I dont wanna replace the cat and then it fail again because i didnt fix the underlying problem.

Ive been driving it in town for a few weeks now, just havent taken it on the highway or for any extended period.

basically i just want to know if i cut the cat is it gonna screw my computer up and cause the car to just not run or run worse?

 

It is very likely that there is an underlying problem that caused the cat failure in the first place.

Are there any stored codes?

I would recommend a full tune up at or around the same time as replacing the cat since it can foul plugs to run with really high back pressure like that. It can foul O2 sensors as well. From there, you just have to keep an eye on things. Maybe do a fuel pressure/leak-down test to see if there are any leaks that may be dumping raw fuel into the intake. Maybe pull the plugs after driving for a few hundred miles to see how things are burning inside.

 

thats the problem.. this garage shop mechanic in town mostly works on older cars. he doenst have any daignostic machines or what not. He suggested i drive it to the dealership or auto zone to have them check for codes or errors.

once again im stuck wondering what to do...

drive it and risk it or cut it off! its 80 miles to the nearest anything thats not a farm or ranch or tractor shop!

basically the only options i have financially is drive it with or without the cat to the nearest town.

just trying to figure out which option is gonna be the best.

I know its illegal to ride without one and you cant suggest i break the law, but sometimes...

"you gotta do... what you gotta do"

 

Your truck has 4 O2 sensors in total. Try removing the O2 sensor directly ahead of the cat and see if it runs better. It will be loud, but it is a diagnostic point. If that lets you get someplace to get things figured out further, so be it.