!!Doug Thorley Headers 4.7L V8!!

Thanks! I'm really happy with it, barely noticeable at highway speeds and not obnoxious around town but has a great grumble at idle and opens up nicely when romping on it

Sent from my Pixel 2 using Tapatalk
 
Questions for those of you that have installed the DT long tube headers without a catalytic converter - Did you need 02 extensions on both front and rear positions or only rear to eliminate the check engine light? Ordered DT long tube and Gibson cat back from Jason Burtman and he told me I needed 4 spacers, but I've heard elsewhere it needs only the rear spacers. Any insight you guys have would be appreciated.
 
I’ve had the DT shorties for a few months now waiting for time to install them. Does anybody happen to know the status of the CARB exemption for these? I was going to just straight pipe my shorties, but I figure if I do that, I might as well sell the shorties and buy long tubes. If they will be carb legal by my next smog test, then I will weld in the factory cats.

What I don’t want to do is hack up my working factory manifolds and then have to buy new ones to pass smog in a year.
 
I’ve had the DT shorties for a few months now waiting for time to install them. Does anybody happen to know the status of the CARB exemption for these? I was going to just straight pipe my shorties, but I figure if I do that, I might as well sell the shorties and buy long tubes. If they will be carb legal by my next smog test, then I will weld in the factory cats.

What I don’t want to do is hack up my working factory manifolds and then have to buy new ones to pass smog in a year.

For anyone who cares, I put in a call to DT and they said that they will probably have an answer on the CARB EO end of September. Apparently their first application failed.

For now, I will be straight piping my shorties because all the DT's are backordered for a long time. If/when they get CARB exemption, I will removed and weld my cats on them.
 
Nortex Raceflow-x exhaust

FWIW I did not get a CEL and did not use the eliminators. DT Shorty headers and magnaflow high flow cats.

Full custom exhaust all the way back, not sure if that matters. The shop that did it specializes in Toyotas so maybe they knew how to space the sensors correctly. I also probably got lucky.

Shared album - Jonathan Stevens - Google Photos

Very interested in pursuing this same header/CAT/custom exhaust modification at Nortex Autoworks. Question, since the install, have you had any issues ? Aside from cost, would you still recommend this set-up? Any issue with exhaust not taken to very end of vehicle (e.g. fumes)? Thanks for any feedback.

Mark
 
Ok so jumping in on this thread. Just starting to notice a bit of bluish smoke on cold start up on my 03. Sounds like I'd better get going on replacing the headers soon next. Just about to roll 300,000 so I got my monies worth! If DT is way on back order, do you just get on that list now or what are you guys doing or would recommend please?
 
For any of those still waiting, I called today to check on the CARB E.O. and still no word back yet, and no indication yet of when they'll know differently.
 
For any of those still waiting, I called today to check on the CARB E.O. and still no word back yet, and no indication yet of when they'll know differently.

:sad::cry2:

Just when i get my hopes up. I guess gotta keep waiting till they get the approval or move the duck out of California. lol
 
You'll be fine if you weld in some cats...

Sorry for reviving this a couple years later, but I've run into the issue of my headers cracking as well and want to go the route of DT. For emissions compliance, is the only option to basically remove and reuse the stock cats?
 
Sorry for reviving this a couple years later, but I've run into the issue of my headers cracking as well and want to go the route of DT. For emissions compliance, is the only option to basically remove and reuse the stock cats?

I'd recommend replacing the stock cats with some high-quality cats like the G-Sport by Gesi cats.

They'll burn cleaner than OEM and will outlast the truck. Buy once, cry once.
 
I'd recommend replacing the stock cats with some high-quality cats like the G-Sport by Gesi cats.

They'll burn cleaner than OEM and will outlast the truck. Buy once, cry once.

So no CEL eliminator if using these cats?

My 06 V8 has a bad cat on the drivers side. Looking to replace those and headers at the same time, but would prefer to use a version that doesn’t throw a code.
 
So no CEL eliminator if using these cats?

My 06 V8 has a bad cat on the drivers side. Looking to replace those and headers at the same time, but would prefer to use a version that doesn’t throw a code.

Correct. I replaced the OEM primary cats with the cats in my signature, didn't need to do anything to clear/prevent CELs.
 
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Thanks for posting - looking at doing a similar setup on my '05. Which Magnaflow cats did you purchase? I've been looking at their web site and it appears there are a number of options, and not sure which specific ones to purchase. Any help you can provide is greatly appreciated. Thanks.

You can see a side built out alone on attached. The other sensor would be just downstream of flange shown in this pic.
 
Shop in NC for installing DT headers and CATs

Does anyone know of a good shop either around Charlotte or Asheville area that can do the DT install with high flow cats so I can pass the NC inspections? Any suggestions/recommendations are greatly appreciated.
 
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How long was longest wait time, I am on four months plus ... with no word of a possible date? (still waiting on Cats and Studs too)
 
I saw they were backordered, but am uncertain as to time-frame. It appears some re-sellers may have the correct ones in stock, but I haven't called to confirm.

How long was longest wait time, I am on four months plus ... with no word of a possible date? (still waiting on Cats and Studs too)
 

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