1985 catalytic converter
Thread Starter
1st Gear
Joined: Apr 2010
Posts: 1
Likes: 0
1985 catalytic converter
Hi, I'm new to this forum and have a question about the catalytic converter on my 1985. The converter may be plugged or starting to plug and I would like to remove it and install a pipe instead. Any problems with this as far as the engine goes or not. If I do this do I need to reattach the small tube on the side of the converter or not. Thanks
Instructor
Joined: Jan 2008
Posts: 217
Likes: 0
From: Coopersville MI
No problems removing it. I banged the inside out of mine versus buying a pipe. It was like a who different car. Before i couldnt spin tires from dead stop with stock 255 tires, now and burn the hell out of the 315's i have on the rear. Have fun!
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
You can do that, your exhaust note may have some unwanted resonance.The tube is probably from your smog pump so you can just tie it up somewhere.
A better solution might be to get a high flow universal cat with a tube for the smog line. I got mine on ebay for about $60.00. That will keep you 50 states legal and the resonance won't drive you nuts.
Either approach will work. Removing a working cat won't make your car faster.
A better solution might be to get a high flow universal cat with a tube for the smog line. I got mine on ebay for about $60.00. That will keep you 50 states legal and the resonance won't drive you nuts.
Either approach will work. Removing a working cat won't make your car faster.
Pro
Joined: Jun 2001
Posts: 520
Likes: 6
From: Elverson PA
It really woke my car up! The cat did fail, so the car had NO power. It would only go about 45 mph floored, and sounded horrible. I think the exhaust was coming back out through the air pump.
Anyway, when I hammered that 25 yr old cat out it woke my car up like I had never felt it before. It was a huge, huge difference. I would think if you got a really good oversized high performance cat that would be the best bet, but that cost money and all... I don't think cats from 1985 were that great, but don't really know. I bet the new hi-po cat would outperform a NOS (new old stock) cat.
I just removed that air pipe when I did the cat.
Anyway, when I hammered that 25 yr old cat out it woke my car up like I had never felt it before. It was a huge, huge difference. I would think if you got a really good oversized high performance cat that would be the best bet, but that cost money and all... I don't think cats from 1985 were that great, but don't really know. I bet the new hi-po cat would outperform a NOS (new old stock) cat.
I just removed that air pipe when I did the cat.
Pro
Joined: Mar 1999
Posts: 678
Likes: 0
From: Oslo, Norway
Hi Remember that gutting the cat make the rcat housing a resonance room that can interfere with the exhaust speed so welding a 3" pipe going through the cat will be theoretical better. Anyway a gutted cat is better than a nearly plugged one.
Safety Car
Joined: Oct 2007
Posts: 4,426
Likes: 229
From: Pennsylvania
I have an 85 with the cat removed and straight through pipes were installed to the mufflers. I have it registered as a classic car, so no emissions are required on it. It does breathe better and sounds great. The air smog pump tube is just left open. It creates no problem. I do get an EGR code once in awhile when cruising at highway speeds. When I shut the car off, the check engine light cancels itself. I've been told it's caused because of the missing cat. I don't know for sure. The exhaust tone is so much better and is not bothersome in the least.
