I have a 1987 iroc that has an aftermarket cat on it. I think its seen better days,its starting to raddle and the car stinks bad.I want to replace it BUT with the orginal style with the air injection tube on it. The problem is the line is completely gone on the car. Where does it connect to? I'm asuming it "T" off the air pump somewhere.Can someone explain were or take a pic? also what is it metal or rubber?Thanks

 

Not really required .
IIRC it only flows air at startup.None of the aftermarket cats use one.
If F-body same as Vette then it is a 1/2" s/s line to the divertor valves at front of engine , pass side

 

Thats not true. You can buy replacement ones with the tube. Stock replacement ones will have it and so will some universal ones.

 

You should be able to find a replacement/aftermarket cat with the secondary air tube.

The problem will be finding the air tube that you're missing. Check the dealer first, then the bone yards.

The tube should hook up to the black diverter box plumbed into the air pump.

 

well honestly I could use maybe 1/2 flex copper and bend it as I need.paint it high temp steel color and who would know.If I really don't need it then I'll just get a aftermarket cat.I like going fast but not stinking doing it.

 

The purpose is to heat up the cat faster so that it works. A cold cat does nothing to the composition of the exhaust. Its possible that it would cool off enough during certain circumstances that having the tube hooked up it would help. If you're going to run a cat on the car, I'd suggest using the tube as well.

 

the tube you're looking for goes down the back of the block on the passenger side and follows the exhaust from there. It is held on by a clamp that is bloted to either the back of the engine or head where the ground strap comes from the firewall. If you have a cat w/o AIR injection on it then it should work without it. If they did what was done to my car then you might have the tubes clamped and welded coming off of the side of the cat. If that is the case your cat will get destroyed, THe air injection system starts the chemical reaction in the cats to clean the air. technology has advanced enough that new cats don't need it but it is still required by federal law. I live in a state that never used to care (I had never even had my hood popped) and now I'm fabricating an air injection system from a car without a trace of it. I haven't been able to drive my DD since july because the PO took out the air injection system. He also destroyed the cats in the process so I have to get 2 new cats too. Hopefully you don't have a dual cat car or the catylitic convert to diverter valve tube will cost you $262 and still only be half the pipe you need.

well gotta go to work in my wife's hyundai I miss my car