Never thought I’d that. I was initially going to chop the end off and add the x-pipe as I like the resonators, but may just custom fab it if it is indeed cheaper.
Doug Thorley headers...successful install stories.
- Thread starter Runabout36
- Start date
Never thought I’d that. I was initially going to chop the end off and add the x-pipe as I like the resonators, but may just custom fab it if it is indeed cheaper.
WhiteSteam
New member
Hi all,I have been readin all the comments here on this post ,i gotta say i am very jealous in a good way of course,for those who had a chance and bought these headers,i keep reading good reviews about it.
I havent been here on the forum for quite some time(2 years or so),and i recently came back,i missed that group buy.
But couple years ago i got lucky and bought a gibson catback exhaust stainless steel version for my 06 v8 sport since my stock exhaus rusted and i almost lost it while driving )))
the sound it a little bit loud for me at around 2k rpm but i got used to it.
id love to install new headers on my runner,i read that it eliminates the noise a little from cat back,gives little more power to a car,gas pedal response improvements...i am missing it in my runner already.
so the question is...
Besides this DT headers,what else is out the for descent price and quality?I am in Pennsylvania,its an inspection state lol so i cant do much modifying.
thank you all for your time and knowledge you lucky owners of DT headers and residents of non inspection states .
I havent been here on the forum for quite some time(2 years or so),and i recently came back,i missed that group buy.
But couple years ago i got lucky and bought a gibson catback exhaust stainless steel version for my 06 v8 sport since my stock exhaus rusted and i almost lost it while driving )))
the sound it a little bit loud for me at around 2k rpm but i got used to it.
id love to install new headers on my runner,i read that it eliminates the noise a little from cat back,gives little more power to a car,gas pedal response improvements...i am missing it in my runner already.
so the question is...
Besides this DT headers,what else is out the for descent price and quality?I am in Pennsylvania,its an inspection state lol so i cant do much modifying.
thank you all for your time and knowledge you lucky owners of DT headers and residents of non inspection states .
doofenshmirtz
New member
URD makes a y-pipe, but it doesn't have CATs or resonators. It is 304 Stainless though and high quality craftmanship, according to buyers.
Magnaflow makes a set of 409 stainless y-pipes that are emissions legal, and use mandrel bent tubing. I got these, and it's definitely an improvement over stock. Unfortunately, the set I got required some refitting. I had a weld bead on an O2 bung thread, and one of the flanges wasn't lined up correctly, requiring the tube to be cut, sleeved, and rewelded.
After having done a LOT of back and forth making my decision, I probably would get the DT y-pipe if I had to do it over again. It doesn't have catalytic converters, but you could have a shop cut those out and fit in cats in their place - or do it yourself if you're already considering fabrication.
If none of these options sound perfect, then custom fab would be best. I was really looking for the holy grail of 2.5" tubing, catalytic converters, and stainless steel, but that option does not exist as an off-the-shelf item
Hanks for the reply. I saw the URD one but $600 for some tubing just seems outrageous to me. I remember when I had my mustang and if you went catless, it was like $150! My shop that does the work for me has a tig, and I can buy sections of either 304 or 409 stainless. I think I’ll build mine seeing as don’t need cats and am going true dual anyways. That will save me a few $$$. Now all I have left is the headers. Just trying to talk myself into dropping the money at the moment lol.
LT1coupe
New member
DT longtubes, DT Y & gibson ss cat back. I used the 90 degree CEL eliminators off ebay with the catalyst in the end, No CEL, not loud unless you mash the loud pedal.
Edit: Just ran a bunch of errands & took my bride to lunch. We both agree it's actually quieter at 55mph than it was before the LT's & Y pipe. The power improvement is very noticable seat of the pants, but there are two rolling hills heading back toward our home that the 4runner normally downshifts to maintain 65mph going up. It didn't today
Edit: Just ran a bunch of errands & took my bride to lunch. We both agree it's actually quieter at 55mph than it was before the LT's & Y pipe. The power improvement is very noticable seat of the pants, but there are two rolling hills heading back toward our home that the 4runner normally downshifts to maintain 65mph going up. It didn't today
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Hey guys,
I have a set of the shorty headers I plan to install soon.
For those of you that went with high-flow cats, how is the highway cruising noise? Was it noticeable?
I want to go with HFC's, but concerned that any drone/noise would annoy me on long road trips. Also, I plan to keep my stock exhaust for now.
Thanks in advance!
-Bill
I have a set of the shorty headers I plan to install soon.
For those of you that went with high-flow cats, how is the highway cruising noise? Was it noticeable?
I want to go with HFC's, but concerned that any drone/noise would annoy me on long road trips. Also, I plan to keep my stock exhaust for now.
Thanks in advance!
-Bill
rdruss
Senior Member
DT longtubes, DT Y & gibson ss cat back. I used the 90 degree CEL eliminators off ebay with the catalyst in the end, No CEL, not loud unless you mash the loud pedal.
Edit: Just ran a bunch of errands & took my bride to lunch. We both agree it's actually quieter at 55mph than it was before the LT's & Y pipe. The power improvement is very noticable seat of the pants, but there are two rolling hills heading back toward our home that the 4runner normally downshifts to maintain 65mph going up. It didn't today
That is really the true test of " did you gain any HP/Torque", something you can measure before/after and "document" improvement as you did.
This thread is amazing. Thanks for all the info gents.
Do you have the part number for this by chance? I'm trying to avoid splicing any eliminators and as previously mentioned the usual o2 bungs seem to be hit or miss.
Do you have the part number for this by chance? I'm trying to avoid splicing any eliminators and as previously mentioned the usual o2 bungs seem to be hit or miss.
High Flow Cats won't have a significant effect on the exhaust sound.
If you're keeping your OEM Muffler and resonator, your truck might actually be quieter than it is from the factory.
When I installed my Shorties and GSport cats, I noticed the truck was a bit quieter after the install. I already had my magnaflow catback installed at this point.
I was told they would work......
My 2005 V8 headers were cracked and leaking and I wasn't sure what route to go for replacement.....OEM.....Doug Thorley......long tube, short tube......aftermarket OEM style..... So I contacted a Doug Thorley dealer and asked them if I could run the 2003-2004 DT long tube headers on my 2005 and that I already had an AIS block plate installed, so I wasn't even using the AIS system.
I get the headers and they look great. After pulling off one of the OEM headers is when I learn the heads themselves have a port for the AIS system. NOT what I expected. I assumed they tapped into the header itself.
So I inspect the DT headers and gasket, and the gasket must work on either AIS heads or non-AIS heads, but the header flange leaves the port in the head open.
I contact the dealer and explain this to them. They gave me the option to exchange them for the 2005-2009 headers....when they get them in....and I pay for shipping the first headers back AND shipping the new headers.
The reason I chose the 2003-2004 DT headers is because they told me they would work.
Now I have to make a decision on what to do:
Returning them is out of the question because of their restocking fee.
Thoughts?
Recommendations?
My 2005 V8 headers were cracked and leaking and I wasn't sure what route to go for replacement.....OEM.....Doug Thorley......long tube, short tube......aftermarket OEM style..... So I contacted a Doug Thorley dealer and asked them if I could run the 2003-2004 DT long tube headers on my 2005 and that I already had an AIS block plate installed, so I wasn't even using the AIS system.
I get the headers and they look great. After pulling off one of the OEM headers is when I learn the heads themselves have a port for the AIS system. NOT what I expected. I assumed they tapped into the header itself.
So I inspect the DT headers and gasket, and the gasket must work on either AIS heads or non-AIS heads, but the header flange leaves the port in the head open.
I contact the dealer and explain this to them. They gave me the option to exchange them for the 2005-2009 headers....when they get them in....and I pay for shipping the first headers back AND shipping the new headers.
The reason I chose the 2003-2004 DT headers is because they told me they would work.
Now I have to make a decision on what to do:
- Wait for the 2005-2009 headers to come in, and pay shipping TWICE.
Have plates welded to the headers I have, to block off the ports.
Drill, tap, plug the AIS ports.
Returning them is out of the question because of their restocking fee.
Thoughts?
Recommendations?
Inv4drZm
Senior Member
There was a thread I was reading where a guy that was swapping a 2UZ into his Lexus car ended up tapping and plugging the injection ports, so it's possible. That said, the engine was on a stand in his garage.
Thanks. I am not sure I can get all of them while in the vehicle, I am pretty sure I can some of them.
DoctorPopcorn
New member
Dabsalot, how did this all pan out for you? Reason I ask, I've been looking for anyone that's installed 03-04 longtube headers on an 05+ V8, with an AIP bypass installed. As Inv4drZm mentioned, I'm wondering if anyone's fabbed a block-off plate for the AIPs using 03-04 headers with no AIP tube.
rattlesnake
New member
For those that have successfully installed the DT headers, is there a need to reprogram the ECU to understand the new exhaust flow? All of these systems are programmed from Toyota from the factory to work together, so it stands to reason that a significant change the the exhaust system would require an update to the engine mapping. If not, I'd imagine there would be an impact to long term reliability and/or performance.
DoctorPopcorn
New member
Please know that I haven't replaced my headers with DT, but with all of the info that I've poured over from a ton of super helpful folks on T4R, I can offer this:
DT longtube headers (deleting upstream cats, connect straight to the Y pipe): you will either need an O2 simulator (URD sometime has one on their website), or space out your downstream 02 sensors with something like this. With LT headers and deleting the upstream cats, can't recall anyone getting around either of these 2 options.
DT shorty headers (keeping and welding either your stock cats, or aftermarket, and then connecting back to the Y pipe): I think some folks still get away with needing no rear 02 sensor trick, but I've paid less attention to shorty installation in reading through posts. I'd imagine it depends on the what cats you're welding back up to the shorties (hi-flow vs OEM-aftermarket).
From what I've read, nothing needs to be done with the upstream 02 sensors, located within the header/manifolds themselves, as they only measure and dictate air to fuel ratios. The 2 downstream 02 sensors read catalytic converter efficiencies, and need to be tricked if any or all of your cats are either old and shot, or completely missing, in the case of installing LT headers.
As I understand it, no tuning is necessary, the ECU will learn and adapt, once, of course, you've taken care of or tricked any 02 issues, if you even need to. There are other folks on here that've had these setups for years that can speak to longevity, and any issues they've come across. Unfortunately, with these trucks & Toyota in general, tuning isn't as simple as hooking up a Cobb AccessPort and throwing an OTS tune on after modding, as I understand it. Of course, if you're moving up to forced induction, that's a good time to get into the tuning game with these engines.
I ended up going with the 05+ Long Tube headers. Probably the best option for my case.
On a related note, I went with the URD O2 simulator and with a little adjusting I was able to eliminate the ‘catalytic converter efficacy’ code. But only since installing the DT headers I sometimes get a P0172 & P0175 code ‘System too rich bank 1 & 2’
