Doug Thorley Headers Tacoma

So, I'm looking to complete my exhaust system and one of the guys I work with recommended this to me for down tubes and mid pipes. Has anyone in the tw ran these by chance im getting a steal 35% off on em cause he worked for them for 12 years. I know its a cat delete and would have to flash my ecu cause the truck will start running super lean but if anyone has any input feel free!

 

Not CARB legal, you will fail smog with those installed

 

Y pipes delete the rear cats but that kit looks like it has a couple catless downpipes, is that the case? that's deleting all four cats. is that your plan?

i have the URD Y currently, rear cat delete and OV tune. i did delete the fronts for a day but i had a leak and couldn't evaluate so reinstalled the stock front cats but am still on the full Y& 3" mid.

 

I mean,

Yeah, I know its fine I have some people in place to take care of that

 

Yeah this is a full cat delete. But i mean is that just too much ? How do you like the sound of yours currently ? And how are you looking with fuel efficiency ?

 

Did you do the ov tune yourself?

 

i have experience with this.

first, none of this is wise in my opinion without a tune, and there is only one choice here: OV. I'm not the only one with that opinion btw. but that is if you are chasing performance.

the only reason you'll want to do a full cat delete, and IMO any cat delete, would be for performance, not for sound.

if you want just sound, go for a TRD catback. easy and sounds great. if you want it loud go for Magnaflow. if you want to split the difference in sound level go for Borla. that's some general consensus here for sound more or less.

if you want performance that is a different question and exhaust alone will let you down big-time.

so what are you trying to achieve?

 

The primary reason is performance. It's just something that's lacking in the tacoma and want to get as much as I can out of it. This will in due time turn into my personal baja truck but for now its part time sand part time d.d. and agree if im not mistake correct me if im wrong. If you don't tune it after deleting cats then thats going to throw off the o2 sensor no ? and yes i know flashing it alone will better the truck but im always looking for more and have the resources to do so minus some experience and someone to flash the truck.

 

i think i did this whole first round of work and have improved my 2GR-FKS with the exhaust flow and power. and I'm about to redo the whole system with a custom tuned Y pipe and a 2.5"mid for the 2.0 version. that will eak out the last bit without opening and customizing the motor itself.

the 3"mid is too big for NA. it loses tq and throttle response in the first half of the range. but the OV tune will help hugely and the tune & exhaust really need each other with this small motor. but with OV on the 3"mid i am still way past stock. the tuned Y and 2.5"mid will tighten up the looseness in the mids at the throttle.

it looks like your truck is AT not MT, is that right? the ATs won't perform very well with the transmission and inability to rev directly into the powerband, so in all honesty i wouldn't bother much with pushing hard and spending cash for performance. the motor and flow will improve but you won't be able to use it in a very exciting way being stuck behind an AT. i would love to show you my truck so you can see for yourself why the MT and rev control matters. with all i put into mine to get it to dance, if it was AT i would put my money into getting a MT if you really love the Tacoma.

 

Oh yeah that would be nice being able to redo your whole exhaust system. But yeah i Was thinking the Y with 2.5 myself personally. But yeah ive been looking to get my truck ov tuned since day 1 but in all honesty havent looked all that hard cause i plan on when these current tires go im going to 33's and just ordered a bunch of stuff for the truck such as the high clearance cbi front bumper, wide body fenders, i already have my 8100 and 8112 bilsteins coming in and looking to get chaos fab upper and lowers. So lots of projects on the truck and doing this exhuast system being one of them. Maybe doing just the lower cat delete would be better and also running the Y Pipe and exhaust system out the front of my rear wheels in the fenders.

 

now that i see your plan, i can make a suggestion. performance for you will make it like a normal mid size like you'd expect. you don't need to go overboard for that with the exhaust. so i think a rear cat delete, Y with 2.5, and whatever else downstream is good with OV. i wouldn't recommend messing with the front cats, there's nothing to gain for you there.

if you really want to go for flow, you absolutely will need open flow media-less mufflers and resonators. media packed mufflers will flat out kill flow on this motor. but if you do go media-less you'll need one or more resonators to deal with the sound. cus it ain't good coming out of the Y pipe and you'll need to deal with it somehow. you can look at mine just to consider stuff. it's always a gamble doing exhaust.

https://www.tacomaworld.com/threads/daves-drivers-truck.659667/

 

Op if your going 33inch then skip the exhaust for last and do the 4.88gear with ovtune. The 3.5 have enough power but it shift too early. The tune will help with that and the gearing will put you where most of the power is.

 

So back to this thread. On the 89229 One of my guys that works for me used to work there and I can get em for 320 but he told me to contact URD (Underdog Racing Development) To get new O2 Sensors because deleting the lower cats will cause a check engine and make the system think it running too rich/lean when it really isn't. Any take on this ?

 

So I got the 33s maybe even thinking doing 35s with the dirt king lower and upper long travel arms and suspension and thats the next thing on my to buy list is the new gears but i'm torn on the option of the 4.8 or the 5.2

 

you're in a 2016 with the 2GR-FKS?

 

Yes, I am a '16 with a 2GR-FKS ! Talking to the guy over at doug thorley. From what I heard they were going to come out with a full exhaust system but never went public with it. I may be able to get my hands on this so we will see but my question still stands. I called them over there at URD and they stated I don't need to change the O2 Sensors Unless I do a full cat delete

 

deleting the rear cats alone doesn't typically throw a code. that would happen with all 4 gone for sure.

 

Okay for sure, Yeah I didn't think it would throw a code since I'm still running cats but lets say for shits and giggles I did full delete on the cats I would need them ? And probably have to tune it no ?

 

I'm not sure, I've seen mention of O2 simulators to accommodate a full delete if there are issues or just trying to avoid the codes.

coincidentally, my truck is torn apart right now getting the stock fronts replaced with the OV 200cell high flow cats. and some other stuff, should be done this week. if i have any codes I'll handle them in vF Tuner. but i don't expect them or tuning issues by now.



the front catless below threw codes, yes, but i couldn't assess any tuning issues, because they were installed wrong and leaked in the cab badly, so were removed the next day.

 

i had forgotten about this thread and jumped back in today without rereading. I'm caught up now, sorry for the repeated question.

anyway, the question i still have for you is what are you doing in the exhaust downstream from the Y pipe? what muffler and/or resonator plans do you have? because the major restrictions in these exhausts are there at the end of the line, not in the beginning. going full cat delete and getting performance really depends on removing those restrictions at the muffler.