Will a early 90's Cat set up work on a 1984? Thanks!

LT1 cats (92-96) are different than L98.

1984-1985 have one style center cat, 1986-1991 are different. The main difference are the mounting flanges. That's why you'll see front pipes or catbacks listed as 86-91.

Thanks. You saved me from an unnecessary road trip and with the price of gas........much appreciated.

Yeah only 84-85 are interchangeable. Now if you get an entire 86-91 system that will work too but may not pass visual. Anything else requires some fabrication.

Like Kevin said, anything can be made to work. I am running a 96 exhaust on my 89, but no cats and there was welding and cutting involved at an exhaust shop.

a lot depends on the emissions laws in your state, pertaining to your car...

I wish CA would leave us older cars alone... there are not that many...

Even getting a 86 catless front Y for my 85 was a trick, because it's not a 50-state legal part.

Did it to upsize to 2.5" and replace a cracked one, and have a 3" round end to adapt to test pipe. Also for CA folks you can get a universal cat that still has the correct EO numbers. All that and the smog tech didn't even look at my $90 etched numbers.

Yup. I live in California so I know the pain. First time I brought my 1955 Willys CJ3B in from Arizona in 1989 they told me it had to be smogged. It has a 1962 Chevy 283 in it that is completely stock with a 2 barrel carb. It passed and haven't had to smog it since.

It's so bad here they make the out-of-state military guys smog their stuff. I was in line at the base for a parking pass and the guy ahead of me from Florida, with a DIESEL, couldn't get a pass, lol. And when I had a new truck, I had to pay a "smog abatement fee". I have to pay a fee to not get smogged. Unbelievable.

FWIW my Corvette passes the sniffer fine with no emissions on it other than a single Carsound cat. No air tubes, smog pump, nothing. Although it's burning so much oil now I think that is going to be the nail in the coffin.

You can do wide open exhaust with test pipe on an 84-85 pretty easily and still be able to revert back to emissions legal if you want. You can buy the rectangular flanges and fab a test pipe, or convert to 3" round instead and use band clamps.

Technically, you can get cited for it, since driving 3k miles a year with no catalytic converter is apparently a notch above torturing and killing protected lions.

Of course I only run my test pipe at the race track. Only takes 5 minutes to swap it. Hold on, some guys in black suits knocking at the door...