Replacing a cat, do it yourself, or leave it to the professionals?

[S_Colt45]

Hi, I have to have my catalytic converter replaced on my 1990 corolla SECA as it has started rattling inside. I went to K-mart auto in Sydney (Australia) and got quoted around Aus $350 (approx US $280) to have it replaced. I haven't rung up anyone else yet.

I was wondering if this is something worth doing yourself, as I know a lot of the cost of having this done is just for the labour. I nearly have the thing off the car (I started taking the exhaust off because I thought that little "box" was just another muffler till I found out what it was

Should I buy a new one or can these be bought second hand? and are there any "issues" that need to be taken into consideration? I have seen one being sold on Ebay (Aus) but it has different connections to mine, there's corrosion at the joint on one end, it might be easier to clean it myself as I don't want to be caught out with any "surprise costs"

The other end towards the front of the cat is welded to the front part of the exhaust. I only have an arc welder and I don't think you can use them on thin tubing as far as I know, and I'm not sure if the replacement cost takes this into consideration.

Thanks for any ideas or suggestions.

Steven

BTY, the exhaust itself is still in good nick over-all, (besides the joint corrosion) no holes or leaks. I got quoted around Aus $750 to do the exhaust, without the cost of the new cat!

[stephiemullen]

Basically you have to take the old cat out and then weld the new one in. It is pretty simple and if you know what you are doing it should only take about 20 minutes or less. I just got a new cat for $105 installed in the US.

[Toysport9601]

I just bought a NEW cat-converter for my 86 Corolla GTS. $40 (universal cat for the OBDO) It will cost me another $40 to have it welded to the existing exhaust system. That is if I decide to. But My exhaust system is kinda old, so I decided to have it re-pipped from the cat-back. $120 at the muffler shop I've always gone to. That is including the new pipping and welding the new cat and also a new muffler welded. NOT BAD!!!

[stephiemullen]

Ok, get this: I put a new 02 sensor and a new cat in my car. I went to the smog station today and the car passed lower than it did when it was only two years old! A month ago it was a gross polluter. Cool huh?