3rd gen AIR system question...

[Mark B]

Hey everyone,
Ive got a 91 RS with a 305TBI. I removed the AIR stuff awhile ago but now I need to pass emissions. I am thinking about putting the air pump back on in an attempt to get the car to pass the sniffer. Heres what I am working with:

-My cat is a new "AIR" cat. It has the air tube but it is pluged right now.
-My headers dont have the air tubes on them.


Im thinking about installing the air pump and hook it directly up to the cat. Should this work? Will it hurt my cat in anyway?


Thanks in Advance,
Mark B

[DeWynter]

To pass inspection you just need to make sure you go for a good long drive first and get the cat good and hot. then do the test and it should pass. The Air is just to get the Cat to warm up faster and to work better on the stock cat. Putting a non AIR cat on would be best but mine passed without the AIR pump.

[Mark B]

Ok... I will tell you the rest of the story.

Last year I had a non-air cat on the car & I failed. A couple months ago, I found that the cat was hollowed out. (It wasnt last year during inspection) So that means that my car is eating up cats. So I replaced that cat with an air-cat in an attempt to get it to pass this year. I also replaced the ECM & Throttle body unit just in case.

I took the car to the inspection place last weekend and failed.

[Mark B]

Here is an old quote from Fred (Injureer)

"The 3rd Gens have a split bed cat with a "reducing" front end (reduces NOx) and an oxidizing bed in the back end (reduces HC and CO). Air is blown in between the beds to feed the oxidizing section. If the back section of the cat goes bad, or if the AIR pump is not working correctly, you can get high HC and CO"

If I hook my AIR pump to the cat directly, it will feed the 2nd bed all of the oxygen that it needs. I think I am going to give it a try. If it works, I will just leave the air pump on there. It doesnt really effect performance & the only reason I really removed it to begin with was to clean up the engine bay. I wanted to get rid of that big diverter valve and the tubes that go into the headers. I will bring it back to the inspection place tomorrow & let you guys know what happens.