swivel socket ,extension, and ratchet
Removing Catalytic Converter 1985 Corvette
Thread Starter
Instructor
Joined: Jul 2004
Posts: 203
Likes: 0
From: Kelowna B.C.
Removing Catalytic Converter 1985 Corvette
How do I get to the top 2 bolts out on the front (nearest the engine)? I removed the clamp and I assume I have to remove the heat shield. I can't get at those 2 10mm. bolts on the front of the heat shield either. Then I can't get at the 2 top 9/16ths bolts on the catalytic converter. I'm removing the cat because after 236,000 kms. It's plugged! Thanks1 J.
Le Mans Master
Joined: Aug 2010
Posts: 9,272
Likes: 17
if you have the rear loose, use a long bar and a hammer , break the rock up in small pieces, start your engine , rev it to blow the pieces out, check to see if they all came out, re-bolt it back up, saves all kind of time
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
You don't have to pull off the heat shield. 
with mtnmanut. It may take a couple of extensions. I don't believe that I had to use a swivel, just a couple of 12" extensions and patience. Once you get the nut off, it will require more patience to remove the bolt from the grip of the heat shield.
I cut the connector that connects the air tube to the cat....you have to tackle that part yet. When I put everything back together with the new cat, I used 1/2" compression fittings to connect the cat to the air tube. I cut the tube about 18" back from the cat and added another compression fitting to make the line up of the tube and the cat easier.
with mtnmanut. It may take a couple of extensions. I don't believe that I had to use a swivel, just a couple of 12" extensions and patience. Once you get the nut off, it will require more patience to remove the bolt from the grip of the heat shield.I cut the connector that connects the air tube to the cat....you have to tackle that part yet. When I put everything back together with the new cat, I used 1/2" compression fittings to connect the cat to the air tube. I cut the tube about 18" back from the cat and added another compression fitting to make the line up of the tube and the cat easier.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
The air tube is attached to the cat with a crimped ring The ring is concave so that it grabs the tube and the tube on the cat. Some on the Forum have used rubber hose to attach the two. I just was not comfortable attached rubber to the cat which gets so hot.
Just so you know, the tube is 1/2" diameter and the compression couplings fit very well. The nice thing about the 85 is that the cat bolts in and out. I take mine out when I go to the track and bolt in a straight through pipe and the air tube bolts right up with the couplings. If you want to see a big difference in power....drop the cat.
I also ended up building my own gaskets. There were no gaskets when GM put this together. Some previous owner had used silicone, but a good exhaust gasket material works well.
Just so you know, the tube is 1/2" diameter and the compression couplings fit very well. The nice thing about the 85 is that the cat bolts in and out. I take mine out when I go to the track and bolt in a straight through pipe and the air tube bolts right up with the couplings. If you want to see a big difference in power....drop the cat.
I also ended up building my own gaskets. There were no gaskets when GM put this together. Some previous owner had used silicone, but a good exhaust gasket material works well.
Last edited by John A. Marker; Mar 16, 2012 at 11:38 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
