mbeltowski

I'm ready to install a new exhaust system on my 77. I found an original catalytic converter that appears to be real clean inside and outside. I want to keep the car as original as possible. The new converters I found are not even close to the original shape and size.

How do I test the converter to make sure it operates as it should? I blew compressed air thru it at both ends and saw no rust or dirt at either end. I picked it up and gave it a good shake and didn't hear any rattles of any kind.

Thanks in advance,

71VetteLover

I would think a visual inspection alone would be good enough. If you have a little "pencil tip" type of LED pocket light it would work great at illuminating the insides.

694speed350

one question Why?

terry82

its junk .it was junk in 1977.i would take a rod to it and open it up .then drive the car and see how bad it was hurting the performance.then if you want buy a new cat and put it on.

7t9l82

Yep I agree with Terry 82. Who cares, throw it in the garbage where it belongs. None of the cars that came with that suitcase full of marbles are worth keeping it on there. If you need a converter get a modern one

Richard454

Here you go-

a test pipe that looks like a cat- not sure if it has the correct NCRS markings though...

http://www.siliconeintakes.com/produ...roducts_id=320

HeadsU.P.

To test cat: Place cat next to tree, leaning slightly rearward. Fire 12 gauge slug into cat.
If slugs goes all the way through, its defective.

mbeltowski

I appreciate the honest replies.

dugsgms74

Theres no test other than visual off the car. Once on the car there are a few tests that can be done but the accurate ones require a exhaust analyzer, the simplest (but not very accurate) is to compare temp on the inlet and outlet, the outlet should be hotter due to the reaction occurring inside the cat.

cv67

Those sucked out of the box; a modern day cat is leaps and bounds better. Those old types were real power robbers think youll regret it;one part when it comes to being original forget about it.

if it operates as it should your car will probably feel slower lol.

mbeltowski

I decided to install the original cat until I have it judged next June. I'll also purchase a new modern high flow cat and replace immediately after judging. I'm looking forward to driving it before and after to see the power difference.

It should be a easy swap since they are flanged on both ends.

Thanks again for all the feedback.