Hi guys,

I recently posted that I am due for a smog test this year, and I really want to pass the first time around. My stock cat's age is unknown, possibly been there the entire life of the car, so I'm guessing it might be a good time for a change.

So, which one is the best?

I need to know from actual experience, or at least heard from someone reliable.

I am thinking about a few, Bonez, Random, Catco, what else?

Keep in mind that this cat has to be durable and reliable for daily driving, plus it's got to pass CA smog (I still have all smog equip, although my stock air box is not there anymore, HKS filter). High flow is a bonus of course.

An additional note: I premix, will that harm the cat? Thanks!

PS: Also posted this in the West forum.

 

What year and trim? NA or TII?

The best cat as far as I can tell is a brand new one. With the high exhaust temps, they tend to start going downhill immediately.

If you're building custom, go Carsound.

If you're buying prefit, Summit Racing has some Catco direct-fit models, but not for the legendary 86 NA Triple Megabuck cat.

http://store.summitracing.com/defaul...h&Ntt=cto-4689

Best of luck

 

I have the Bonez Superflo System on my 90 N/A GXL. I only have one cat now (main-cat), instead of the 3 that come with the stock configuration and I still passed PA emissions with flying colors ("PASS" across the board)

 

Oops, sorry, forgot to post that mine is an 87 TII.

 

I've got a Bonez superflow single on mine too, I haven't done an emmissions test, but most people who have the same cat and have had emissions testing say it passes with flying colors, even in California.

 

got a magnaflow main cat and passed easily

 

CA smog passed catco 2 cat system here, cats are still in good condition but the exhaust gaskets supplied suck.

 

I had the Bonez Super-Flo on my '89 n/a, which passed with flying colors.

 

I managed to turn the insides of my Bonez into molten slag in about 15k miles somehow.

 

The Bonez single won't pass CA emissions if they do the visual inspection (they're supposed to).

And my Bonez on an NA lasted less than 18 months before it was all hollow inside - yep, the cat matrix was in the mufflers in little pieces. The stock cats were inefficient but intact after 12+ years.

The Catco system is basically a stock replacement.

The Bonez is a "high flow" system (really high flow if you wait long enough).

There's also Random Technology ( http://www.randomtechnology.com/ ), but it looks like they don't have the full kit for any FC, just the "main cat".

 

Thanks for all the info guys!

I am looking to replace just the main cat. I do still have the stock precat, which I can pop back in. Current concern is that my stock cat maybe toast since I started premixing a while back, and some guys on the West Coast forum said premixing will toast a cat quickly.

So, the Catco, is it same quality as the stock? I would imagine no.

Since no one has tried the random, I guess I may be the first one then.

Thanks again!