I was having my Banks Exhaust installed on my 88 Iroc Convertible (305 TPI/Auto). When the car was up on the lift, I noticed how small the cat was. When I commented about it to my mechanic - he said he thought it was small as well - to use his words, it looks like it would be something found on a 4 Cylinder car.

When I mean small, it was perhaps only 9 inches across and about 1' long. Is this the size of a high performance cat? Is this a OEM cat? Do I have the wrong cat on the car?

I appologize for not posting a pic - but I didn't have a digital camera when I bought it to my mechanic.

 

Worry about the inlet and outlet size of the cat more than its oversize. If it is anything less than 3" it sucks.

 

A positive was that at least the outlet was 3" as the banks exhaust intermediate pipe was able to be welded on directly.

Can someone post a pic of the stock/OEM cat that is suppose be on the car?

 

Here is what the stock y-pipe and cat look like off of a TBI car. I am not sure what exaclty the TPI stuff looks like but I think it is just a slightly larger version of this.

 

Yea the tpi stuff looks the same just a little bigger. The catco hi flow cat that is on the car now is smaller. It in the upper right corner in this pic.

 

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Here is a shot of my 3" cat-co cat as well.


The difference between aftermarket and stock is night and day.

 

Thanks for all of the great pics!

It looks like I lucked out and the previous owner had installed an aftermarket cat.

I just had hand my banks exhaust system hooked up (with a 4th gen rear tips) and it sounds and looks great!

Of course the shop charged my $180 to install it since they wound up having to do "extensive welding" to get everything lined. Not sure if that was a lot to have a cat back installed (the previous system was welded in place as well) but I'm happy with how it turned out : )

Thanks again for all the pics!

 

Does the catco add more sound?I want my car a little louder and was thinking of a cat.

 

Increasing the diameter of exhuast piping increases the sound. Not the cat alone.

 

lmao! yea I got a hp cat, looks like that stock one up there in the first pic. 100% flow! I took a sword and gutted it right out. Of course this may create hot spots in the exhaust pipes causing it to pop, but those seem to of gone away now that its resinated. There was a big difference in sound after I gutted it, small performance, probably some 3-5hp gain that I'll never notice lol.. anyway...