non cali cat with doug headers opinions?

[sleepydad]

rambling ensues

I'm doing a new motor so I have it out right now.

I have a set of doug headers I'm putting on because heck it's easy when the engine is out.

however I need to modify the cat pipe as per the doug instructions. honestly I think it's pretty stupid and I would guess they would sell way more of these things if they did not design it this way but... options are limited with headers and 5vzfe. guessing they just assume if your doing this your going to get a wide band.

I'm leaning toward getting a new aftermarket generic cat and having an exhaust shop I have worked with modify it. I just don't have the equipment to modify it myself.

the Toyota cats are crazy out of this world expensive, I just can't justify it. well I could actually.

option 1
the doug headers x-over pipe already has a O2 spot in it but... I'm guessing the wires are not long enough to work and I would have to modify the wires... not a good thing probably.

option 2
is get a direct fit like a walker or magnaflow and have them hack it up.

option 3
use my existing cat and hack it up... but if I ever do want to go back I would not be able to use it and it's expensive as hell to get this one again. part of me says leave this one alone.

shot of the doug O2 location vs the OEM cat o2 location for reference.

<a href="https://imgur.com/YCKMKa2"><img src="https://i.imgur.com/YCKMKa2l.jpg" title="source: imgur.com" /></a>

 

[MN4runnerman]

If your interested I could get a walker cat through work. It’ll be cheaper than what rockauto lists. I’ll look tomorrow.

 

[Tyler James Inc]

Why do you think the O2 wires aren't long enough? Is the location that far off? Hard to reference when the two pieces are so different.
Dose the kit come with the other half of that flange at the back of the crossover pipe? I definitely think just use the factory cat off that. They might be super expensive new, but these rigs are getting parted out every day. In the unlikely event you go back to a stock setup, you shouldn't have a tough time sourcing a stock used one.
Shit, yours could probably use replacing anyway!
If you don't have emissions testing you need to pass, I'm changing my opinion to going the Magnaflow route [emoji23]

 

[Scramble]

Cat's are cheap now, get one off Amazon & hack it up. I remember when my cat went back in 04, dealer wanted $1200, GTFO! LOL Bought one online for around $360. Now they're $200, you'll never go back to stock DT headers rule. One of the first Mods I ever did. Super simple on a 3RZ.

 

[BrianSD_42]

If your cat isn't bad then perhaps just keep it and weld+hack to fit.

 

[gamefreakgc]

The mechanic who installed mine (I can't weld) routed it like this:

He put his own piping in, welded it to the frame and blocked off the DT O2 port (which does work fine btw) and instead kept the existing O2 port.

My opinion is to hack up your existing catalytic converter. Mine's welded in anyway, no bolts here. Pretty common if you live in an area that had catalytic converter thieves.

 

[sleepydad]

If your interested I could get a walker cat through work. It’ll be cheaper than what rockauto lists. I’ll look tomorrow.

I’m going to hit you up tomorrow

 

[sleepydad]

Why do you think the O2 wires aren't long enough? Is the location that far off? Hard to reference when the two pieces are so different.
Dose the kit come with the other half of that flange at the back of the crossover pipe? I definitely think just use the factory cat off that. They might be super expensive new, but these rigs are getting parted out every day. In the unlikely event you go back to a stock setup, you shouldn't have a tough time sourcing a stock used one.
Shit, yours could probably use replacing anyway!
If you don't have emissions testing you need to pass, I'm changing my opinion to going the Magnaflow route [emoji23]

I’m going to put the engine in and see if the Doug location works. If it does I will have them just make a custom cat. Should be pretty easy.

It’s hard to tell but I think the stock wires will reach. The engine exhaust moves around a little bit so slack is needed.

We shall see

 

[sleepydad]

Cat's are cheap now, get one off Amazon & hack it up. I remember when my cat went back in 04, dealer wanted $1200, GTFO! LOL Bought one online for around $360. Now they're $200, you'll never go back to stock DT headers rule. One of the first Mods I ever did. Super simple on a 3RZ.

Curse u and your 3rz. I did look for one when I was truck shopping. They are kind of unicorns in 4wd. I agree it seems cats are pretty cheap.

 

[sleepydad]

If your cat isn't bad then perhaps just keep it and weld+hack to fit.

It’s not bad but it is 18 Year’s old and has god knows how many miles on it. It’s just my thinking that if I have to pay somebody to make a custom cat then might as well get a new one.

I really have no idea how long cats last but everything wears out eventually. With my luck lately I would go 500 miles and start getting codes for dysfunction cat.

 

[sleepydad]

The mechanic who installed mine (I can't weld) routed it like this:

He put his own piping in, welded it to the frame and blocked off the DT O2 port (which does work fine btw) and instead kept the existing O2 port.

My opinion is to hack up your existing catalytic converter. Mine's welded in anyway, no bolts here. Pretty common if you live in an area that had catalytic converter thieves.

This is exactly what I wanted to know. I’m going to grab a new new one from my secret supplier.

Thanks.

 

[BrianSD_42]

It’s not bad but it is 18 Year’s old and has god knows how many miles on it. It’s just my thinking that if I have to pay somebody to make a custom cat then might as well get a new one.

I really have no idea how long cats last but everything wears out eventually. With my luck lately I would go 500 miles and start getting codes for dysfunction cat.

I’ve got to 245,000 miles, passed CA smog on original CAT and truck runs great with plenty of HP.

Maybe you will benefit from a new CAT. Maybe you won’t.

I wouldn’t toss a real working Toyota cat on the assumption an aftermarket will perform better. There is the risk it will perform no different eg money wasted, the risk it will perform worse, the risk it will perform worse and throw codes.

But hey maybe if you do replace cat keep the original just in case.

have to pay somebody to make a custom cat

You mean pay someome to weld custom piping onto the cat connecting to the exhaust right? The cat is untouched it is just an easy connect the piping weld unless I am missing something. While you are welding down there it may be a good time to add a Tundra resonance silencer. The rare mod that knocks out drone.

I have Downey headers (no longer sold) and to mount them to the exhaust required a few modifications and $s to my mechanic / fabricator.
.