Catalytic Converter

The catalytic conveter uses a catalyst to convert (hence the name) a bunch of bad gasses (CO and HC's) into normal atmospheric gasses (H20, C02, and 02). Mine went bad. Had to be replaced.

(Old caty on left. Big hole caused by years of use and heavy oil consumption. Check out the bolt hole on the right side. That bolt was stuck in there solid. The last 1/4 of the threads are still in the hole.)

The day I remember realizing it was bad was when I punched it onto the main road from my apartment complex and I saw all these black pebbles rolling all over the road behind me and going fast. Everytime I shifted the car and hit the gas more would come out. This continued for a few shifts, and then stopped. After shacking the car up for another couple months, rebuilding the engine, and putting in headers, I finally have good reason to replace it (if I replaced it before the rebuilt I would've destroyed it again in days because of heavy oil burning).

There are certain laws you should be aware of concerning catys and their replacement none of which I will take time to add to this page (they have to be new and OEM and meet certain performance requirements and much much more).

Normally, a nice big hole like this would help things out, but one huge chunk of the loosened material was clogging up about 1/2 or 2/3 of the rear outlet of the caty, causing major exhaust restrictions. I'm hoping (which I should find out tomorrow, 01 Dec 2000) this was the cause of my poor little Z only pulling hard to about 5K and then wanting to quit. This may also have been the cause of several exhaust leaks I had because of excessive backpressure. This problem probably also cause the major exhaust vibrations that rattle my car to heck.

Well, here is the new caty converter.

Nice, heh. I bought it for $69.19 plus tax from Carparts.com. The normal price is $115 or so...they'll price match the same caty from DiscountCarParts.com (where it sells for $78) and then give you another 10% off because of their 110% price guarantee (match then beat by 10%). The part is Walker MFG Co. Product: CATALYTIC CNVTR-DRCT F (#15537).

This caty is supposed to be a DIRECT FIT to (at least) my '84 NA. I cross checked and found this converter does fit several others, including turbos.

It isn't exactly FULLY DIRECT fit. The orginal had threaded bolt holes, whereas with this one, you will have to purchase a couple high-grade bolts, nuts, and washers to connect it, but it is pretty easy. The caty also came with two converter flange gaskets that have compression rings on the inner side. A very limited warranty also applies.

The flanges are actually free floating and are kept on by a lip.

(you get two of these :)