Just have a few questions about exhaust and as they come with answers I'm sure I'll have more....my first question really being it is dark outside right now and I found on my way home from work my rattling cat which I know is the inside catalyst is plugging my exhaust up and I need to know some aftermarket cats to use to cut this one out and get a new one put in...I have a welder and also a Sawzall so I can cut it and weld in new. My first option is this 590250 FLOWMONSTER 2.5" Universal Catalytic Converter
Will this fit? I'm not sure the length at the moment and need to order one asap. Does my 2000 4.3 4x4 have a bung welded into the down stream cat for an O2 sensor? I'd like to just cut it out and put the new one in with exhaust clamps for now and weld it on layer down the road. Please help!!!! My gas milage has dropped drastically and performance is suffering!!

 

No one?

 

Cutting and welding would work.

Are you sure the rattling isn't a loose heat shield? If the only symptom is noise, that's far more likely.

A collapsed catalyst usually causes a huge drop in power, and very high exhaust temps. You can also test with a vacuum gauge. Check vacuum at idle, and at 3,000 RPM's in Park or Neutral with no load at all (AC off, etc). Vacuum should be higher at 3000 RPMs with no load than at idle with no load. If there's less vacuum at 3000 RPMs, you have an obstruction in the exhaust.

If the problem is the cat, your weld-in "universal" cat could work.

 

It's a huge loss in power it has been rattling with no heat shield for a year now it's an obd 2 for sure...it's a 2000 model year. I was just curious about length and 2nd O2 sensor really I am a mechanic for profession so I have all the tools I need to do the job. Has anyone replaced theirs in a 2000 with a weld in? If so where did the cuts get made and what length did you use I know there is a hanger post cat and am worried about keeping it. Being the welder I have access to is an hour away and want to keep the rigidity of the exhaust system

 

OK. I'm the one who is stupid here. In my defense, I got "95" from your profile name.

I've never looked on a 2000. Checking parts sources, you get a lot of metal and a lot of catalyst for $200 +/= $30 with a complete bolt on replacement.

Personally, I'd cut as close as possible to the failed part of the cat. Do you know if it's the upstream or downstream part that has collapsed?

 

It's the down stream side

 

Lol weren't saying you were stupid in the least...I had a 95 and got an upgrade to a 2000 with leather and such lol no name calling here!!

 

Well, I just looked. There are a bunch of different cats for that year, depending on combinations of 4wd/2wd, 4door/2door and "S bend" or no "S bend" after the downstream cat.

I don't see O2 bungs on any of them near the downstream catalyst, but there is a hanger on most of them right at the exit of the downstream cat.

If I tell you to take pics, you'll probably figure it out when you see it.

Besides, the mail just got here, and a couple of gaskets I was waiting on are in that. I need to run and get mine back together now.