Da Coupe

iTrader: (7)

I'm currently doing a w58 swap on my 1uz and my slave and clutch fork cannot be installed without hitting the stock cat. I was thinking about placing them where the forward mufflers are right after the tunnel but I think they won't generate enough heat to function properly. They need a good amount of heat to work right? I would also have to move the 2nd pair of 02 sensors behind the cats. The car is a 98 and since I live in Cali I do not want to just delete them. For guys with IMF or Rush headers where are you guys relocating your cats?

mr2tosc4

iTrader: (1)

Good question. I'm doing the IMF-w58 right now and just plan on putting a center cat after the Y merges. Will one center cat be enough to pass emissions, I don't know yet. I'll leave the downstream 02 sensors where they are for now (I'll have 4 02 sensors before the cat, which is stupid) and see if I can pass emissions that way. I'm OBD1 so it might be different for you since you have a 98.

spdrcr771

iTrader: (21)

Those cats would def not fire off, being that far back. My question is how much is the driverside cat in the way. Is there a way to mod,it to fit. Meening like cut the flang of the cat & angle it to give you the clearance. The thing is, if you move both cats after the 2nd O2 sensors, then your gonna have to fab up some down pipes off the stock manifolds. Thats even more work. I just got done installing my new PPE headers on my 98 & I bought 2 new magnaflow shorty cats w/o flanges & had PPE cut me new flanges. Then I was able to tilt the cats more upward to give me more ground clearance & also clock the bottom cat flanges to where you can get easy access to the bolts. Im thinking you could do this & fit the tranny & keep the cats in the stock location.


I dont think the one center cat is gonna be enough.

here's a link to those cats. http://www.magnaflow.com/02catalytic...niversal=49956

I got mine off Ebay for $79ea

Here's my exhaust thread, you might find some pics that might help.
https://www.clublexus.com/forums/per...-98-sc430.html

Da Coupe

iTrader: (7)

Hmm... one center cat actually sounds like a good idea. The stock cat definitely won't fit. It's around 4" clearance from stock header to slave bleeder screw. Even if I angle it up it's just too long. I might be able to fit an aftermarket one though. The smallest cat I could find are 8" long with 4" center section and 3" total diameter which are magnaflow 50005. I can cut them to make them even shorter. BUT they're 2.25. If they don't fit then maybe I'll route em next to the tranny. How come you don't think one cat will be enough? Flow restrictions or emission wise? BTW I read your whole thread about your new exhaust setup. Very nice and informative.

spdrcr771

iTrader: (21)

Yea emissions wise. Its too far back to work like the front ones. The 3rd cat is a Cali thing, which meen the cars cat/O2 sensor set up is still the same. 1st set of O2's are for fuel mixture. 2nd are to make sure the cats are working properly. The 3rd cat is just to dumb down the emissions even more. There's not O2 sensor after the 3rd. Having the stock 3rd one by itself is like not having one at all, as far a emissions go.

Im trying to come up with something, but I cant see what you got. Do you have any pics to post.

Da Coupe

iTrader: (7)

I really appreciate your help in all of this. I took some photos and I'll load em up tomorrow. I tried taking the pass side cat off today and stripped 2 lugs and rounded 1 nut. So... I ended up yanking out the motor. Didn't wanto to fuss with taking the manifold off which I don't think is even possible with the cat attached. Besides the motor could use alittle freshening up. It was my first time removing the 1uz and it wasn't as involved as I thought It'b be. So I guess after I decide what to do (just replace gaskets or crack it open and do fresh rebuild) I'll get back to the exhaust situation once the motor is back in. Looking at my header options... I think the s&s and ppe are the only ones that'll fit. The pipes on the IMF look alittle too long before they merge. The ppe and s&s should be the same length since they "bolt" up to stock exhaust system right? I know you had both