Cat converter removal

Torxx · Post by **Torxx** » Mon Sep 11, 2006 8:55 pm

Same rep at IAP said removing the cat converter would not be worth the effort. Increase in power would be negligible.

Any comments or first hand experience.

Thanks

mbouse · Post by **mbouse** » Tue Sep 12, 2006 12:34 pm

I believe you have a '79, right?

I have an '80 (carb'd). I replaced my cat with a "test" pipe and have NEVER been happier with the improved response. I am seriously considering doing the same with the '78 this off season.

NOW, that is not to say that a current technology replacement cat will have depreciable effects on performance. I have heard that many new cats of high end quality perform their task with little significant change to overall performance.

No emmissions testing done in the mitten state, so i can get away with it. check your requirements before proceeding.

Torxx · Post by **Torxx** » Wed Sep 13, 2006 10:11 pm

'79 is correct. no emmisions testing in VA, with antique tags there is no yearly inspection either. I know removing the cat is not legal, but..... uh...

I won't be doing it myself and do not know if it will be hard to find someone to do the changes?

I have read that stock header, resonater, and an ansa pipe is a good set up. Does that sound right?

What do you mean when you say test pipe?

So Cal Mark · Post by **So Cal Mark** » Thu Sep 14, 2006 1:12 am

"test pipe" is the legalese for a shop to remove your cat. Since it's illegal according to Federal law, any shop that removes it is liable, so they write the work order up as a testing procedure.

Using the stock manifold and merely adding an Ansa muff will change the sound abit, but won't do anything for performance.

mbouse · Post by **mbouse** » Thu Sep 14, 2006 12:06 pm

mark is dead on about the change in muffler=little or no change in performance. i changed my muffler to an ANSA dual tipped free flow. nice change in sound, but no discernable performance change.

you will immediately feel a change in performance if/when you get rid of that stock cat; if you are going to either a NEW technology cat, or a straight pipe. new cats are less restrictive, yet sacrifice zero ability to perform their intended functions.

my muffer shop REFUSED to consider a test pipe. i was lucky to find a straight pipe, and did the work myself. it is a piece of cake on a '79. six bolts removed, drop the two springs (if they are still there) and the old cat drops to the floor...six new bolts and nuts and the straight pipe is in.

WOW, especially on a cold engine.

Torxx · Post by **Torxx** » Thu Sep 14, 2006 8:16 pm

Forgive me if I sound a little slow on the take..

If there is a stock header, cat conv , and ansa pipe in place now. will simply removing the cat and replacing witha straight pipe make a noticeable diff.?

i am not sure about the origin of the cat conv, and not sure if there is a resonator (i gather the resonator is mostly about the tone). How do I identify if I have one?

mbouse · Post by **mbouse** » Thu Sep 14, 2006 8:53 pm

yes

the resonator is on the pipe in front of the muffler. looks like a miniture muffler. if stock, it is before the axle and after the cat.

see email for the rest of the story

lanciahf · Post by **lanciahf** » Sun Sep 17, 2006 9:02 am

At least IAP is honest. I bought a test pipe from another vendor with no such warnings. I replaced my converter with the test pipe and the car felt immediately less torquey. Converter went back in and torque was restored. My car has Bosch FI.

mbouse · Post by **mbouse** » Mon Sep 18, 2006 1:05 pm

my '80 carb'd Spider did not act the same. i advocate trying the test pipe.

which, by the way IAP does not sell. might be a connection there