URD MK3 Full 304 Stainless TIG Welded Exhaust & Y Pipe V8 4.7L
- Thread starter Formidable
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Formidable
New member
rdruss
Senior Member
I have an "03 V8 and bought the Magnaflow y-pipe/cat combo, haven't installed it yet as the effort looks to be more than the payback until the stock cat fails. It was $166. It definitely looks a lot more unrestrictive than the stock but it would be interesting to see before and after HP numbers on just the y-pipe, no other exhaust mods.
I'll put a picture of it on my garage.
I'll put a picture of it on my garage.
NNV4Runner
New member
I would love to do the URD y pipe. butttt I'm not quite there yet. maybe in the future... need to run the 1/4 mile first.
anyways, I tried using the search bar with no luck, has anyone installed an Exhaust Cut out? There's a perfect spot right after the flange to the Catback. before the stock muffler, so you'd just be running Cats, "when you wanted to."
anyone have links to threads or something? much appreciated.
p.s. and for that matter, is there a drag racing thread in here?
anyways, I tried using the search bar with no luck, has anyone installed an Exhaust Cut out? There's a perfect spot right after the flange to the Catback. before the stock muffler, so you'd just be running Cats, "when you wanted to."
anyone have links to threads or something? much appreciated.
p.s. and for that matter, is there a drag racing thread in here?
Inv4drZm
Senior Member
URD is 304 stainless TIG welded and deletes the stock 2 cats so they can route the driver's side under the transmission pan to merge with the passenger side.
Doug Thorley is 409 stainless MIG welded and replaces the stock 2 cats with 2 resonators but otherwise follows the same path as stock; under the t-case.
Sounds like URD is higher quality and the pipe does not droop below the cross bar? and also noticed that The URD off road Y Pipe does include ports for the rear O2 sensors. It will not cause a check engine light from eliminating the rear catalytic converters. To my understanding, the Doug Thorley's y-pipe needs o2 spacers for the rear o2 sensors to get rid of the check engine light?
I have on order the Doug Thorley premium headers and looking into either getting Doug Thorley y-pipe or URD. Just trying to decide which is best.
I have on order the Doug Thorley premium headers and looking into either getting Doug Thorley y-pipe or URD. Just trying to decide which is best.
Last edited:
Inv4drZm
Senior Member
The rear cats that are eliminated with the URD are not needed for the electronics and will not cause a CEL when removed. Both Y's have O2 bungs and both should work as long as you keep the manifold cats. The DT LT headers delete the cats so you'll need spacers or simulators in the Y pipe regardless, to my understanding.
As far as the URD drooping below the crossmember, I'm not sure.
Thank you for the clarification. With the DT LT, regardless, i'll need spacers that Jason will include with when I get the headers. I guess, there's not much difference to warrant the extra $160 by going with the URD over DT besides different welds.
DoctorPopcorn
New member
About a month ago, some nice person cut out my driver secondary cat, so my frivolous purchase was warranted. I have to give them credit, though- they made beautiful cuts with whatever blade they were using. Cut my O2 off at the wire, so I still had the plug connection, thank god.
So, I thought about welding custom pipes, getting rid of both secondary cats, looked at the DT Y pipe, but the resonators look too similar to cats and I figured someone might come along and cut one of them out again. Why not spend the $600 and do it right the first time for a lifetime part. That, and I just wanted what was supposed to be my daily driver back, after I bought it because the rear diff went out on my '98 (which is now fixed, but now needs an alternator).
So even though it's spendy, I landed on the URD Y pipe. Granted, it's worth every penny for my situation. The fit was fantastic and the metal work is beautiful. I drove my truck around without the cat for damn near a month with an Xmas tree on my dash. I was sure I had blown out my Air Injection switching valve, as after the install I was still throwing a P0037, P0057, P0102, P1440, and P1443. Turned out to be the 20A EFI fuse that had blown. Switched that out, had two new Denso downstream O2s, and all my dummy lights were cleared and stayed cleared with my code reader. No O2 issues at all, BUT, we have no emissions testing here in MN.
Taking off the factory Y pipe from the catback, one of the bolts snapped, even with the impact on "gentle". So, I was riding around for 5 days with no catback and the new URD Y pipe. A bit quieter than having a secondary involuntary cat delete, but still loud. Got new Bosal hardware and gasket from Napa today, mounted up nicely, but the fit still isn't perfectly flush with the gasket fitting into the factory catback, even with gentle use of the impact. We'll see how long before that gasket blows out, and I don't attribute this as an issue on URD's end, as the gasket fit perfectly onto the Y pipe. Maybe the old gasket is still on there. My stock catback has a rusted-out and missing tailpipe, and a hole started on top of the muffler.
So after all that rambling, the URD Y pipe, mounted up to the stock catback works great- at least for my situation. I drove for a month with my truck on limp mode, but as far as I can tell, acceleration and response feels more smooth to me, but who knows. It's a bit throatier than stock, but still quiet, in terms of what I was dealing with before. No more stolen secondary cats to worry about, and even more incentive to get DT longtubes. I still like the idea of keeping my shi**y, rusted-out oem catback. Maybe I'll rig up a side-exit down the road. Anyway, hope this might help someone else, down the road.
So, I thought about welding custom pipes, getting rid of both secondary cats, looked at the DT Y pipe, but the resonators look too similar to cats and I figured someone might come along and cut one of them out again. Why not spend the $600 and do it right the first time for a lifetime part. That, and I just wanted what was supposed to be my daily driver back, after I bought it because the rear diff went out on my '98 (which is now fixed, but now needs an alternator).
So even though it's spendy, I landed on the URD Y pipe. Granted, it's worth every penny for my situation. The fit was fantastic and the metal work is beautiful. I drove my truck around without the cat for damn near a month with an Xmas tree on my dash. I was sure I had blown out my Air Injection switching valve, as after the install I was still throwing a P0037, P0057, P0102, P1440, and P1443. Turned out to be the 20A EFI fuse that had blown. Switched that out, had two new Denso downstream O2s, and all my dummy lights were cleared and stayed cleared with my code reader. No O2 issues at all, BUT, we have no emissions testing here in MN.
Taking off the factory Y pipe from the catback, one of the bolts snapped, even with the impact on "gentle". So, I was riding around for 5 days with no catback and the new URD Y pipe. A bit quieter than having a secondary involuntary cat delete, but still loud. Got new Bosal hardware and gasket from Napa today, mounted up nicely, but the fit still isn't perfectly flush with the gasket fitting into the factory catback, even with gentle use of the impact. We'll see how long before that gasket blows out, and I don't attribute this as an issue on URD's end, as the gasket fit perfectly onto the Y pipe. Maybe the old gasket is still on there. My stock catback has a rusted-out and missing tailpipe, and a hole started on top of the muffler.
So after all that rambling, the URD Y pipe, mounted up to the stock catback works great- at least for my situation. I drove for a month with my truck on limp mode, but as far as I can tell, acceleration and response feels more smooth to me, but who knows. It's a bit throatier than stock, but still quiet, in terms of what I was dealing with before. No more stolen secondary cats to worry about, and even more incentive to get DT longtubes. I still like the idea of keeping my shi**y, rusted-out oem catback. Maybe I'll rig up a side-exit down the road. Anyway, hope this might help someone else, down the road.
rdruss
Senior Member
Would still like to see a before/after dyno with JUST y-pipe replacement. The stock y-pipe on '03 V8 admittedly looks restrictive as heck, but after watching that video of the guys smashing a set of headers to what appeared to be down to at least 50% of the original area and seeing no difference in HP on the before/after dyno test I would bet no difference between y-pipes either.
If there is, I'm all in as I still have a Magnaflow y-pipe that's a couple years old in the basement but I don't feel it's worth the effort to install just because it looks less restrictive. Will wait until I have to.
By the way, the URD system looks great!
If there is, I'm all in as I still have a Magnaflow y-pipe that's a couple years old in the basement but I don't feel it's worth the effort to install just because it looks less restrictive. Will wait until I have to.
By the way, the URD system looks great!
Kryptoroxx
New member
I've done the dt shorties and welded the stock cats on. Also installed the urd y pipe but I have left the cat back stock for now.
I don't have a dyno currently and I couldn't measure gains because I don't have a starting point but WOT definitely feels better and she squats a lot harder than before. I would be interested in the cat back exhaust but I think the wife would castrate me if I pulled the trigger right now.
Throttle response feels a little better as well. It takes a lot less effort getting on the interstate. I can't attribute exactly what to what since I did the headers and y pipe simultaneously but I am holding my breath on the claimed better mpg. Honestly seems about the same but it could be a little better honestly. Just holding my opinion till I have data on it.
Sent from my SM-G986U using Tapatalk
I don't have a dyno currently and I couldn't measure gains because I don't have a starting point but WOT definitely feels better and she squats a lot harder than before. I would be interested in the cat back exhaust but I think the wife would castrate me if I pulled the trigger right now.
Throttle response feels a little better as well. It takes a lot less effort getting on the interstate. I can't attribute exactly what to what since I did the headers and y pipe simultaneously but I am holding my breath on the claimed better mpg. Honestly seems about the same but it could be a little better honestly. Just holding my opinion till I have data on it.
Sent from my SM-G986U using Tapatalk
eric merryfield
New member
Over two years on mine, great product!
I've had the cat back urd system on my 08 v8 since Mayish of 2019 when my over the axle pipe broke.....it instantly made it fun to drive. Likely the best update I could have done. You do notice it when your towing a 24 foot trailer, it helps with MPG a touch.
Added a sprint booster and its even more fun.(turn this off for towing!)
This spring the stock y pipe fully broke and was replaced with the URD Y pipe. Haven't noticed as much of a change with this, but its a very good and LIGHT pipe.
Last on the list will be to install on the 08 is the full Stainless long tube Thorleys from the group buy a couple years ago.
I also have a 05 V8 that came with the thorley shorties, I put the same cat back URD exhaust on, its quite a bit quieter than the 08 maybe its the headers? Or it just needs so more driving , this spring it got the Thorley y pipe, a good 10 pounds heavier that the URD, good pipe also. Super smooth and responsive throttle even with cooper 255-80-17's.
I've had the cat back urd system on my 08 v8 since Mayish of 2019 when my over the axle pipe broke.....it instantly made it fun to drive. Likely the best update I could have done. You do notice it when your towing a 24 foot trailer, it helps with MPG a touch.
Added a sprint booster and its even more fun.(turn this off for towing!)
This spring the stock y pipe fully broke and was replaced with the URD Y pipe. Haven't noticed as much of a change with this, but its a very good and LIGHT pipe.
Last on the list will be to install on the 08 is the full Stainless long tube Thorleys from the group buy a couple years ago.
I also have a 05 V8 that came with the thorley shorties, I put the same cat back URD exhaust on, its quite a bit quieter than the 08 maybe its the headers? Or it just needs so more driving , this spring it got the Thorley y pipe, a good 10 pounds heavier that the URD, good pipe also. Super smooth and responsive throttle even with cooper 255-80-17's.
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