So im able to score an oem new oem cat for $65 off an 88 300zx a guy had in the box never used stashed away for over 20 years. Im hoping to get some flanges on my pipe to bolt it up on my 92 max as I seem to go through these magnaflow cats almost every etest it seems. I noticed the oem cats go for $800-$1000 so I couldn't pass it up. Im hoping this cat will last unlike the aftermarket that im throwing money into and when talking to others I've heard the aftermarket are known to only last a couple years before the substrate inside is burnt up and useless. Guess that's why magnaflow only has a 2 year warranty.

 

Are you using Magnaflow high-flow cats?

There's no reason an OEM style replacement aftermarket cat shouldn't last indefinitely. Now if it's a "high-flow" cat then yes you'll forever be in squeaking-by-on-emissions territory.

 

Yes its the magnaflow high flow cat. Good to know. So I should probably stick with oem or oem aftermarket going forward then im assuming? unless i want to be replacing the high flow every couple years before the test. The oem cat I found is new never used for an 88 300zx but when looking at the shape it appears to look about the same size as what I've been using in the past but I may just have to add some pipe and flanges to make it work being the cats I've been using have just been mig welded straight onto the pipe with no flanges.

 

Well what I'm saying is that the high-flow cats aren't going "bad" it's that they're always dubious on emissions passing capability to begin with. They're almost useless in that sense because you don't quite get a truly high-flow system OR easily passing vehicle emissions wise.

 

I actually had the magnaflow high flow on it when it failed and replaced it with another high flow but the numbers did significanly drop when it passed but the oem looks like it goes new from nissan for $800-$1000 so i couldn't pass up the deal for the oem cat at $65. I figure next test if it fails i'll put on the oem and i could always swap back to high flow if i decided i suppose but im not really sure there's that much loss of power with an oem vs. high flow.