No cats N/A?

[1tacoplease]

Delete Catalytic Converters N/A?

Anyone running this setup, no catalytic converters? What do you like dislike? Notice an increase/decrease in power, torque, and mileage? I'm already running long tubes so my primary cats are deleted, but considering getting a Y pipe and deleting secondary cats.

Currently have:
URD TCAI
URD MAF Calibrator
JBA Long Tube Headers
Stock Y pipe
Gibson 2.5" catback exhaust
URD performance thermostat
Denso IKH20 plugs
URD fuel pump upgrade kit

Thinking about a Y pipe or an intake manifold spacer. What are your thoughts?

 

[1tacoplease]

So, everyone running no cats is F/I?

 

[Sasquatch95]

There are lots of people running no cats N/A and they all saw good gains from a y-pipe. Y pipe will just make it louder but more power and torque

 

[hrspwr236]

Don't forget the rasp, I did the rear cat delete and it is raspy as he!! Need to look into getting a resonator and or weld in a magnaflow muffler with along with what ever muffler you may have unless it's stock when you have no cats at all!

 

[Slywhitty]

This is urd y pipe/ 2nd gen Doug thorley long tubes and magnaflow catback. It's loud lol. I do plan on eventually adding a resonator or second muffler but for now I like making people mad haha

http://youtu.be/WCZlQPw9ThQ

 

[1tacoplease]

I went ahead and bought the intake manifold spacer and am considering the URD 4x4 competition Y pipe instead of the DT Y pipe bomb and if there is too much rasp, I'm thinking of adding 1 resonator to the catback pipe.

 

[hrspwr236]

Sounds like a great plan, just do it!

 

[Red-XR-Pride]

youll need a maf cal to tune with or its gonna run super rich. i just did this about 2 weeks ago. intake long tubes and ypipe
and then you gotta street tune it or dyno tune it.

 

[1tacoplease]

youll need a maf cal to tune with or its gonna run super rich. i just did this about 2 weeks ago. intake long tubes and ypipe
and then you gotta street tune it or dyno tune it.

Thanks, I have a maf cal and as soon as I do it, I'll get it tuned. Which Y pipe did you use?

 

[TommyXrunner]

running full catless exhaust and an intake i noticed a decent gain on the butt dyno and averaged 30 miles more per tank before the gas light came on

 

[Fish_On]

You really need to have it tuned to run a catless exhaust with o2 sims? I have an afe intake and MKII catback and URD ypipe. I was about to buy headers and o2 sims from urd and hadnt heard anything about needing a tune to make the truck run properly...

 

[Torspd]

No, you don't have to have it tuned.

Depending on which intake you have, it might be something you want to do, but that is intake related.

Tuning, would be because you want to optimize the AFR commands since Toyota made the OEM tune extremely rich, and or you want to adjust the timing map. Not because you are running cat less.

 

[1tacoplease]

Thanks Torspd. My maf cal is tuned for my intake already. I am also running the O2 sim from URD and everything is running great with no CEL.

 

[1tacoplease]

Another question for everyone running catless and then adding a muffler or resonator. Doesn't this defeat the purpose? Or, could I add a high flow catalytic converter for proper back pressure? I ended up purchasing the DT Y pipe bomb. Thanks.

 

[hrspwr236]

High flow cat would be better flowing than stock but still legal, as long as the muffler or resonated is straight through design it is still less restrictive than a cat.

 

[1tacoplease]

So what would be better for performance on my N/A truck, a high flow cat, vibrant resonator, or a chambered muffler (like a powerstick, glasspacck, or turbo muffler, I believe they're all the same type of muffler)?

 

[hrspwr236]

I depends on your driving style, if you don't haul a$$ everywhere and all the time my preference would be to leave the stock cats so that normal driving around town you can keep your power band lower in the rpms, the loss in back pressure will move it higher in the rpm range and unless your pushing your truck above 3k all the time I say leave everything as it is now with the y pipe and a straight through muffler

 

[1tacoplease]

I hardly drive above 3k rpm's but I got a brand new Y pipe just sitting here and I would love the added performance. I was even thinking of installing the Y pipe and using a cat from stock and placing it right before muffler.

 

[hrspwr236]

Install the y pipe, won't affect you that much, I wouldn't recommend installing another cat keep the factory set up for when you sell the truck.

 

[Brother Lu]

I depends on your driving style, if you don't haul a$$ everywhere and all the time my preference would be to leave the stock cats so that normal driving around town you can keep your power band lower in the rpms, the loss in back pressure will move it higher in the rpm range and unless your pushing your truck above 3k all the time I say leave everything as it is now with the y pipe and a straight through muffler

Will the x be much louder with a straight thru muffler? I noticed some owners are doing a muffler delete. How does that sound on a stock system? When I read these threads it makes me believe that the stock cats are what keep these engines from being loud and rapsey and droney.All things I dislike.