Rattling Catalytic and replacement

[peeeot]

The catalytic converter on my my '91 Cutlass Supreme has an obnoxious metallic rattling sound whenever the engine is under load at rpms in the 1500 range and at idle. I've already removed the heat shield so I know the cause lies within the converter itself, and I'm only going to be able to tolerate the noise for a limited time.

 

I'm considering replacing the converter with a Magnaflow universal because it is supposed to be a good high-flow catalytic AND I can get a new one off of ebay for cheaper than any other cat I've seen.

 

What do people think of this product? Will it reduce my fuel economy at all?

[birdman]

i know the dynomax cats are really cheap too. fuel eco. should be the same.

[Speed Stick]

I just cut my cat out and replaced it with a resinator along with a cheap bottle muffler. Thats odd that your cat is making that noise, weird...

[Supreme Cutlass]

Are you sure it's not the tranny? My car rattles from time to time (filter & fluid helped) and I used to think it was the cat. I found out it was the transmission later.

[Psych0matt]

Thats odd that your cat is making that noise, weird...

 

Mine has done that since i bought the car almost three years ago. my plan is to get a resonator and put it in instead of another cat, unless i can find a good high flow for cheap enough

[peeeot]

I'm pretty positive it's the cat because if I reach under there and knock on it I hear it rattle. I just replaced the transmission fluid and filter and nothing was loose in there that I could tell.

 

I'd like to replace it with a cat for the sake of emissions inspection. The magnaflow was selling on ebay for like $53, which is an excellent price for a cat as far as I've seen.

 

I'm surprised that Psych0matt was able to pass inspection with the cat rattling like that; from what I've researched, it usually indicates disintigration of the catalyst which means the cat isn't working right. I guess some inspection people aren't as thorough as others...

[89GP_SE]

just cut out the cat and put in a peice of pipe... why would you want to put another one in there

[peeeot]

I'd never pass inspection without one.

[89GP_SE]

how often do you have to do inspections... i never have to do inspections.. ever

[Psych0matt]

I'm surprised that Psych0matt was able to pass inspection with the cat rattling like that

 

Michigan = No emission inspections

Indiana = No emission inspections

Since I've owned my car, it's never been emission inspected

[jdcutty]

Well, just take it off, hollow it out, and put it back on. It makes it look like you still have one, but you dont.

[peeeot]

won't it show up in the emissions inspection though? You know, where they stick the probe in the tailpipe and measure the exhaust content?

[jdcutty]

won't it show up in the emissions inspection though? You know, where they stick the probe in the tailpipe and measure the exhaust content?

 

I dont know, I also have never had to do that. Gotta love Michigan