Couple shots of the fitment on my 09 V8.

Note that I have an aftermarket cat-back with an additional resonator between the muffler and the flange connecting to the y-pipe. The location/angle of that pipe is close to stock, but not exact. If you have a stock cat-back exhaust, it's possible it may fit up higher under the truck. I'm not running skids, but from looking online I think I'll be okay when I add them later by running a couple spacers.

The pipe is hanging about 3/4" below the cross member, not great but not bad either.




I'll get around to creating a video eventually. Have a drive at the end of the week that I made 2 weeks ago. Looking forward to see if I pick up an MPG or two.

Thanks for the pics, and posts. I don't always see all the replies here. When I get an email notification and I'm in a rush I reply but again sometimes miss other posts.

If you have a fitment issue or question for the 03-04 Y pipe, call Doug thorley at 800-347-8664. Ask for MIKE and tell him Jason sent you and he will go over it with you, etc. and will help.

Also, if anyone needs a Y pipe, call or text me at 717-319-2100 to order, etc.

Yesterday I ordered this from Jason, a new build thread to be born.

That's what I was afraid of with this question … silence.
Why go thru the aggravation if there is no measurable benefit?

I can tell the difference on start up. Truck roars to life with a very deep growl. Butt dynos are subjective, but I feel at between 3k and 4500 rpms it pulls better. The problem with any expectations of measurable power gains is it costs money to tune and dyno. We are the first ones to put these on our trucks. DT has been producing headers since the 1960s, so I think they have a pretty good idea how exhaust flow works. Looking at a cross section of the OEM crossover tells me that my engine will breath a whole lot better. Is this enough juice for the average person to go through all the aggravation and expense? Not for most. We don't have the luxury of dozens of performance aftermarket parts being produced and tested like say a small block Chevy or Ford. We do these mods in the hopes that our soccer mom SUVs will gain some punch. Toyota performance costs money unfortunately. If someone wants to donate a stock V8, do a baseline dyno run, put 33 to 35 inch tires on it and do another dyno run, put intake on, tune and dyno again, put exhaust on, tune and dyno again, we would have concrete numbers to advertise for these products. You see the logistical and financial problems this would present for most of us? Hell lets put a go fund me account together, buy a truck and donate it to DT and let them experiment for awhile. Even then there is not enough interest for DT to put much R&D into a project like this. These pipes make power, but until some real world proven numbers are published, there will always be people who disagree that they make any power at all. I'm sure someone will disagree with this post as it is. There would be people who disagree with actual dyno numbers being accurate. This is not like an interior led swap where you can take a picture and show everybody. It's a leap of faith I was willing to take and have been happy I did.

So initially, I haven't realized any significant gains in MPG. But the truck feels better/happier than before.

I've noticed a SIGNIFICANT reduction in the number of times the truck drops out of 5th OD into 4th OD or 4th when on the highway.

The truck sounds great now. Quieter at idle, real low rumble. Not quite as raspy on wide-open throttle either. Note that I have done a good bit of exhaust work before the y-pipe, details are in my signature. I'm happy about it so far.

Nice to hear some type of positive feedback. But I disagree somewhat with what you say. If DT can't afford to dyno a stock V8 4Runner to get a baseline and then install a set of their longtubes for a comparison and then install their Y-pipe and dyno once more, then they must not be charging enough for their product.
They could document things like: exhaust temp before/after, back pressure before/after, obviously HP and Torque before/after, and throttle response to name a few. Then they could a least give customers an idea of what to expect. If that would break their bank then ???

Well, I kind of was thinking out loud, so I guess it's a theory lol. No one knows how much R&D they put in this. I just don't think it was a top priority. Jason helped them get a donor truck to have these Y pipes and headers built. I'd be curious to know what numbers people have gotten out of the Tundra or Lexus. But, with all the retro Muscle Cars now available, as well as the Drift crowd, custom builders and race teams out there, I just think a 4Runner is not high on the list for R&D.

I certainly don't want to be negative toward DT, they did the $runner crowd a big service by stepping up and providing a reasonably priced alternative to cracked OEM exhaust manifolds and one would have to believe there is performance to be gained from their headers and probably from the y-pipe as well.
The icing on the cake would be some performance numbers.
Thanks DT and JasonB for your efforts!

Super noob question............

On the headers that do have a CARB number, is there a difference in performance compared to those without? Im not in California or even a smog state, so it doesn't affect me, Im just wondering should I be looking at only headers that aren't CARB compliant? I see a lot of DT headers are.

I was happy to help. With you guys helping and me at the wheel, we got the headers done and the Y pipe, and a lot of fronted cash. Again, I enjoy what I do and have a Premium version Header group buy going right now for those that don't have headers yet....

Group buy for Doug Thorley PREMIUM VERSION headers, need 20 people! - this will END in about 5 days! If you want these, let me know! On this one, I fronted a ton to get this started and we currently have close to 30 people that are buying this premium version.

All good. THere is a Dyno I posted that's 32 HP and 30 Ft lbs of torque! That was for the shorty headers! Yes, impressive. They don't do dynos for add on pieces like a Y pipe. They never have. My good guess it probably 7-10 HP and it does help with better gas mileage with the headers, etc. People buy the Y pipe for 2 reasons.

1) They offroad and want more clearance over the stock Y pipe which sits lower than it should.

2) They want more power/better gas mileage. The stock Y pipe is like sucking through a straw and Toyota super bent it in and cut corners.

They have ALL been submitted for carb approval, it just takes TIME. No worries on that.

If anyone wants a Y pipe/headers, call or text me at 717-319-2100 and I'll help you out.

I’m looking for a flange I can use to attach the upstream of the DT y-pipe to the new headers and cats I’ll be installing.

So, this flange will be welded onto the section of the pipe from below the new cat and will connect the headers to the y-pipe.

Any ideas?

Standard 2.25" 2 bolt flat flange will mate to the ypipe nicely with remflex 6006 gaskets between. I had shorty headers with 2.5" pipe and 2.5" flange and it was slightly too big to mate to the factory or DT y pipes, 2.25" would have been ideal.

Thanks for chimin in to help.

Also, Y pipes are coming back into stock shortly. if you have a 03-04 or a 05-09 and need a Y pipe, call or text 717-319-2100 and i'll get you setup.

I have a 2003 v8 4runner. I bought the shorty DT headers, Magnaflow cats, and Gibson catback from Burtman about a year ago. I also got spacers from Burtman to go with the new Denso sensors I bought. I didn't install anything until about two months ago. At the time I was prepping the install I contacted Jason to make sure I was doing the whole thing right and at that time I learned that DT also had a Y pipe available. So I also bought the Y pipe but since I already had the shop scheduled to put the rest in I used the stock Y and planned to swap in the DT Y pipe when it arrived.

With stock Y pipe in - Seemed like the car was more spirited. Never checked MPGs. Happy with performance. Good sound on start up and at most RPMs. Unfortunately terrible drone at about 2000 RPMs which is where I am at highway cruising speed of 65 mph or so. Unacceptably loud. I hoped that the DT Y pipe with its two resonators would alleviate this. Interestingly the shop installed the new sensors into the bungs at the end of the headers but did not install the spacers or new sensors into the bungs on the Y pipe, yet I did not have any CEL or codes. Everything worked fine.

DT Y pipe - Doesn't fit if everything has been put together to fit the stock Y pipe. It might fit if everything goes in at the same time - don't know. According to Jason and DT the DT Y pipe is supposed to fit if the stock Y pipe fit. It doesn't. I contacted Jason who basically acted as an intermediary between me and DT but didn't really have any solution. So I started dealing directly with DT and sent them a bunch of pictures. They sent me an '05 Y pipe to see if that might fit better. It didn't. So the shop I was having do the work had to do some fab work to jerry rig in the Y pipe that DT sent. Interested if anyone else had this problem or if it just dropped right in. BTW, my Y pipe is the reworked version that is supposed to maintain maximum clearance. I may have had one of the first versions of this as Jason mentioned that they had just reworked it. In any event, not sure why DT didn't get this right.

With DT Y pipe in - I did not perceive any noticeable difference between the stock Y and the DT Y. Car still drives great. Drone at 2000 RPMs is still terrible. The shop still didn't install the spacers or new sensors this time. They just swapped the old sensors from the old Y to the new Y. This time I do have CEL, VSC Off, VSC Trac lights coming on. I am going to put in the spacers and new sensors and see if that fixes the computer issues.

Side note - I checked the forums and discovered that the flanges on my stainless steel headers are not stainless and that they will rust over time. This was disappointing to learn. And it was even more disappointing that Jason didn't give me a heads up on this when I contacted him before paying to have the headers installed and also didn't give me a heads up about the all stainless steel versions (including flanges) that were being made.

If anyone has any great ideas on how to get rid of the drone I am very interested in hearing them. I did some research on the interwebs and may try adding a 30" resonator tube T'ed off of the pipe between the muffler and the end of tailpipe.

Hopefully this helps the people considering this mod.