Need a new catalytic converter

[BirchyBoy]

My bank 2 converter is shot. I'm going to do the replacement myself, either in my garage at a garage where I can rent a lift for a couple hours.

I keep reading about Magnaflow and Flowmaster. I'm on a tight budget (thanks for the $1,300 repair, Acura), so Magnaflow is out. The Flowmaster gets good reviews except for the additional O2 sensor holes that need to be plugged. From what I read, they are non-standard thread and do not come with the necessary plugs. For the folks that have used them, what did you use to plug the holes?

Here's what I've found on Amazon:
Flowmaster, comes with the hardware except for O2 plugs, $312
Walker, no hardware, $264 plus a $50 rebate debit card
AP, with hardware, $327

The garage I usually go to doesn't like Magnaflow and said that they use the AP brand. I had never heard of it; they said it wasn't available unless you worked for a shop. Low and behold, 5 minutes on Ebay and I found the brand at a reasonable price.

I need advice on which one to go with. I'll also be ordering 3 new O2 sensors; I replaced one of them a month ago. I'll be towing, so if any offer a power improvement over the other I'd appreciate that input as well. I'll do a cat-back muffler later this summer, hopefully.

---------- Post added at 10:03 PM ---------- Previous post was at 09:46 PM ----------

Maybe I was too worried about the extra 02 holes based on reviews from Amazon. It looks like they may be standard metric size, M18 x 1.5. Can anyone confirm?

 

[livingez_123]

If you have an extra hole, just weld it up.

 

[BirchyBoy]

Thanks. I've found that I can get a metric bolt and plug it.

My concern now is the manifold flange bolts. I don't have the tools to deal with an issue if one of the bolts breaks off. I might have to take it to a shop and have them weld a replacement in, as much as I hate to do that. Unless I can find a shop that will install a new system if I bring it in.

 

[BirchyBoy]

I had a new Magnaflow single converter welded in today for $220. Seems to run a little better; I'm hoping my mileage will come back up again as well. Going to have the same shop do a Magnaflow exhaust with 3" pipe soon.

 

[laredo1307]

I just did the same work on my 96 Tahoe myself. I purchased the Flowmaster cat system. As far as the removing the flange bolts you need a really long extension and a lot of strength. All my bolts came out ok except for one which gauld up the threads of the flange on its way out. I bought a Helicoil kit and rethreaded that one, then took the old bolt and chased the threads. Soak the everything in Kroil as soon as you can.

For what it's worth Flowmaster and Magnaflow is all branding. There are better manufacturers out there.