Cat replacement help needed

[MTGen]

Hello!

I have a 2002 Subaru Legacy with 167,000 miles. About a year ago the CEL came on. Drove it fine for about eight months then the car started cutting out when stepping on the gas. I took it to our mechanic and the codes showed P0447 (EVAP vent open) and P0130 (O2 sensor circuit problem B1 S1). I had those problems fixed and the car ran great, only thing is one week later the CEL came on again, this time the P0420 cat inefficiency code showed up. Our mechanic said the cat needed to be replaced and quoted $720.00 parts and $87.00 labor. We're in Montana and I've been checking out replacement cats on rockauto.com and partstrain.com and thinking it would save a whole lot to just do it ourselves.

So my questions are:
1. Does anyone have any experience replacing their cat themselves and have any advice to offer, such as brand that worked out okay, other parts needed besides cat etc.

2. Is it likely to be able to easily replace the cat and get the CEL to stay cleared after?

We are getting ready to sell this car and would like to get this problem fixed and the CEL clear beforehand....thanks for any help you can give us.

[Legacy777]

Welcome to the BBS.

The 420 code from the cat inefficiency can be a cranky code, and may not be a complete indicator that the cat is bad. You may want to try replacing the rear O2 sensor or at least testing it.

I know catalytic converters can go bad, but I wouldn't say it's something that happens all the time. You could also try clearing the code and see if comes back. If you have a scan tool, you can clear the code, or try and remove the negative cable from the battery.

Maybe someone else can also comment.