I have to make an 2JZGE NA-T emissions compliant for state inspection. Right now it has a 3" turbo back straight pipe so I have to install a cat. I really don't know much about converters as far as size and efficiency go. For example, if you look at this catco listed on Summit's site it rates it for up to a 5500 lb vehicle.
http://www.summitracing.com/parts/cto-6907/overview/

So that cat would be good enough for a 3/4 ton pickup. BUT those are typically going to have a larger V8 engine, which means more exhaust volume. You guys think something like the one listed will work? In OH they are really critical on NOX and CO2. Any suggestions would be appreciated, cause I can't get plates until I pass eCheck.

 

Your best bet is to find a oem cat and get it fabricat to fit, I know most of those aftermarket ones don't work well for emissions. I know you can even add this stuff to your gas to help pass too.

 

An OEM cat would be like 2.25". I can't neck down a 3" downpipe into that and then flare back out to 3". Catco says their converters are 50 state legal. So I guess I need to call Summit and ask them point blank which 3" cat will pass emissions.

 

If you're on the state of California just make sure to install OVDII

 

Ohio is nowhere near as strict as the smog patrol in CA. But they require you to have a CAT on the car and if you get pulled over without one... BIG fine and they tow your car. But in order to get plates you have to pass emission testing (they drive it on a dyno and have a tailpipe sniffer). Either way I need a cat or it won't pass.

 

Emission is such a scam, i deal with the samething, colorado has the road sniffers when your driving lol

 

Tell me about it. There are only 11 counties out of 88 that require it in my state and for some dumb reason I reside in one of the 11 lol. Soon I'll escape this nonsense!

 

I came from florida and going in to a state with emissions is stepping back in time in the 80s lol.

 

^^ So did I. From completely lax to completely draconian.

DrBrown54, I'd recommend an OEM rear cat and an OEM front MKIV TT cat for best results (and weld into your exhaust system) unless your diameter is larger than a factory TT exhaust pipe now. A random fact is that all MKIV TT's used the same 50-state cats and therefore should be fine for passing emissions elsewhere. For aftermarket cats I think Catco and Magnaflow do some of the better ones. Not sure which higher flow models to recommend other than Random Technology. The trouble is that 49-state aftermarket cats often don't have as much platinum as OEM cats came with and this doesn't always render them as effective.

 

This is an NA-T setup, so the entire exhaust is custom. The downpipe right off the turbine is 3" all the way out to the tail pipe. There's zero chance of me welding in a 2.25" cat. That would be a massive bottleneck so I'll have to do an aftermarket one. Most of the catcos are a slip fit so in theory it should be as simple as cutting the existing pipe and slapping a couple clamps on it.

 

any updates on emissions?

 

Out of 88 counties mine is one of SEVEN that still test exhausts!! Unbelievable lol

I talked to a salesman at Summit. Their OEM cat for the 2J was rated for 6500 pounds. So we settled on this:
http://www.summitracing.com/parts/cto-2517

I debated building another catback and selling this one because it's too pretty to hack up but I really don't time right now and I have to get plates on it soon so I'm going to chop off the 16" resonator that is where the cat normally goes and put in the converter with clamps. I'm juggling cars in the garage so hopefully this week I'll get the cat on there. The exhaust sounds so good right now and the cat will make it too quiet most likely. That's my biggest gripe!

 

Move.

Really, if I couldn't have custom exhausts on my cars, I would be very unhappy. My straight-through exhaust was one of the reasons I loved my SC4.

 

All in good time my friend! My investments didn't pan out the last couple years so building my future house did not pan out. I've put the project on hold and hopefully in 2 years I'll be living in my new house. May be a good thing cause a big fat mortgage would seriously cut out my future mods on the SC!

 

what I did on mine is take the midpipe and have a cat welded in there. that worked for several years until one station said, you are supossed to have 2 cats. so I welded another one on the midpipe and I have been good since (the second one was just clamped on for quite a while actually was fine but ugly).

I use the 3" universal magnaflow ones you can get online or on ebay even. There are a few versions like long ones short ones oval ones but I found just the generic 3" regular size fits well and is a better deal than the others.

Welding on a stock cat would be hilarious. no way I would ever do that on a na-t.
using a gte cat will still be a huge restriction, its the first thing gte owners take off and get a downpipe. stick an aftermarket highflow cat or 2 on the midpipe, I have passed with just 1 before but if the place is picky on visual throw 2 on there or remove the underhood sticker that they read to find out how many cats / o2 sensor you are supposed to have. you can still make a bunch of power with 1 or 2 or maybe the second one is not working so well. I have another midpipe with no cats on it for the track etc.. so I can actually tell the difference, with no cats the spool is better but you can pretty much smell your own car when you stop, and so can everyone else, tradeoffs I guess.