Cats or no cats on my 03 2UZ? (Poll)

So I recently scored a used URD o2 simulator that has solved my several years long PO420/PO430 issue.
Technically my 03 will need to pass TX emissions inspection until Jan 2027. But I'm seriously considering chopping the cats off and straight piping from the JBA long tubes into the TRD catback. I'm wanting a little more power and sound. I already removed the resonator.
TX doesn't do a sniffer test. Just plugs into the OBD2. So the o2 sim should pass inspection. My mechanic doesn't do a visual inspection and honestly doesn't give a shit lol. He's the one that recommended I tried the o2 spacers. Anyways...

Whatcha think?

 

I'm not taking any legal responsibility from what happens......















do it.

 

Put some electric cutouts in place of the cats, then you can have a "loud" switch on the dash.
https://www.summitracing.com/parts/sum-670112-2

 

Too much work and money

 

I doubt theres much gain removing the high flow cats. Maybe at 7500rpm, but not below 5k.

 

Might be worth it for the extra rumble noises

 

$60 New BackFire Dual Universal Automotive Exhaust Flame Thrower Fire Throwing Kit Muffler

https://www.amazon.com/BackFire-Uni...465521d3e78e3851827c6c528214a416&gad_source=1

 

Anybody have any real world experiences with straight pipes on a 2uz?

By that I mean straight pipes where the cats should be.

 

You know those loud af chevy trucks that sound great at idle (if you like a choppy cam) but sound like dogshit the rest of the time?

i bet that how straight pipes would be on a 2uz. Decent at idle & full throttle, but garbage in between. Needs 11:1 compression & a cam rowdy enough to need new valve springs.

 

To clarify I just meant straight pipes where the cats should be, but with a muffler.
Are you referring to just straight pipes?
I've heard a few trucks with no muffler and they sound terrible, IMHO.
My buddy had an 01 tundra with the stock exhaust chopped after the resonator and a turn down pipe. Sounded like dog shit IMHO.

 

If you want to go that route, hollow them out instead. Not exactly legal but much less likely to get caught since an inspector only needs to look under the vehicle to see if they exist.

 

If they were the old OEM cats that were failing, that would be ideal. But since my mechanic DGAF (as mentioned, he recommended I tried the o2 spacers to beat the inspection computer) he doesn't care about the visual inspection. Just gotta trick the state computer.

Anyways, since these cats are new, if I remove em, I'm scrapping em for some $, or keeping em just just incase, until Jan 2027, then scrapping em.

 

Plus if anyone looks under they'll see the o2 sim and the o2 spacers anyways.

 

Do they really stand out?

 

Don't worry, this was just a testing phase.
I went back and zip tied the box to the top of the transmission cross member and sucked up most of the slack in the wiring harness.

 

It doesn’t make sense why they would do it there when it could be done in the dash.

 

I’d be tempted to leave the cats, even though you’re truck is a “dedicated offroad only vehicle”. The cats can still do their job, and it’s not like our stock 4.7 engines produce enough HP to gain any perceivable power gain by deleting them.

 

Holes in the hood.

 

This one's not the off roader. This one is the lowered street queen. Goals are to make it faster.
Eventually I want to do a remote mount turbo, cams, and 05-06 intake manifold.
4.10's and new LSD this August. Maybe do the manifold then too.

Probably do the GX brakes as well.

 

Leave cat. When you go turbo ditch them. Fi hates backpressue until then any potentisl fine is not worth it. Will u make more powervw/o them....yes. but. I would not risk it. Just my .02.

 

I vote no cats and a 'Burble Tune'...

Cued: Remote start pre-tune:
https://youtu.be/uPJWd5KRksU?t=46

Cued: After full tune:
https://youtu.be/uPJWd5KRksU?t=467

Cued: Cold start after tune:
https://youtu.be/uPJWd5KRksU?t=549

 

The fuck is a burble tune?
Also the 03 is currently un-tuneable without a piggy back or stand alone ECU.

 

Good on the clean up of the wiring... knew you could do better
Looking at the poll... Your cutting them anyway aren't you

 

Haha undecided at this time.

 

Cut em after the turbo adding project post 2027 to keep you and your mechanics noses clean. All fun and games till the ticket books come out.

 

See attached videos....

 

I was at work before. But now I heard em, those sound terrible.

 

When I replaced the entire exhaust on our Civic I accidentally purchased the SoundFX versions of resonator AND muffler. (might have been the cheapest?)
When you open it up it sounds like i'm driving some teenagers hoopty rice burner.

 

Do it...

 

I'm thinking about running a fat pipe & resonated tip.



need to cut off and rehang the hangers, and make an adapter cone.