Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers

Would you like the DT headers to have a Highflow catalytic converter?

  • Hell no! Open and loud.

    Votes: 35 9.1%
  • Yes, I would like to be legal.

    Votes: 283 73.9%
  • I don't care either way as long as I get them!

    Votes: 65 17.0%

  • Total voters
    383
mind sharing your costs?

Headers - $650 shipped (URD's end of year 15% off sale!)

Sensors - $300 shipped (Denso brand. I replaced all 4 sensors while it was all apart....I wasn't having any issues with my old sensors, but figured I would replace them while it was all apart since I have 136k on the odometer)

Shop Time - 8hrs. I won't quote the install cost because labor rates change and vary by location....I believe anywhere from $75-125 depending on the shop. But figure on at least 10hrs....maybe more.

I could have saved some money and skipped replacing the sensors or installed them myself later. I also could have skipped the bung install. Anything thing extra that you request takes time and time costs money, but I always like to do things once the right way to avoid issues/time down the road.
 
Thorley Headers

So I'm getting my headers from Thorley; and when talking to Mike, if I understood him correctly, they are now welding on a piece of steel tubing onto the stainless header so that the weld to the existing cat pipe is easy for any muffler shop etc. So they wouldn't have to work with a stainless to steel weld.
 
So I'm getting my headers from Thorley; and when talking to Mike, if I understood him correctly, they are now welding on a piece of steel tubing onto the stainless header so that the weld to the existing cat pipe is easy for any muffler shop etc. So they wouldn't have to work with a stainless to steel weld.

Did you receive your headers from Thorley? Any luck getting them installed yet?
 
As someone else mentioned, after any header install on any vehicle after a month of 2 tighten up your mounting bolts, studs or nuts. Do so with the engine at normal operating temperature not cold.
 
It is very tight with the steering shaft but the headers should fit. It'll be a ***** if a stud breaks tho. Email Doug Thorley to be sure but there's no differences to the Canadian 4runner that I know of. Not sure about the F code but a P0430 (OBD-II Trouble Code Information and Diagnosis | Engine-Codes.com Catalyst System Efficiency Below Threshold Bank 2. Your cat is no good or one of 02 sensors is not reading correctly. If its leaking exhaust between the 02 sensors that may cause it, I don't know. I would probably replace the manifolds, inspect cat, if it looks good on the inside, replace sensor, if the cat is blow out replace it. Or since you going headers, go with high flow cats for the hell of it :lookout:

Also in Ontario and just got my first 4runner. Looking at replacing the exhaust manifold (cracked) with the Thorley headers (or possibly a set-up from DirtyDeeds) and the rest of the exhaust. I saw you'd had a lot of work done on your V8 - did you have any issues passing the emissions test? Just want to make sure that if I spend this much $$ I won't have any issues.
 
I looked them up and found their site:

Stainless Steel Shortie Headers, 2005-09 Toyota 4Runner, 4.7L ? Doug Thorley Headers

I don't need to replace mine as of now but if I do I will definitely be buying these and having a local shop do the install.

I know that I could probably do the install myself save the welding part, but If a bolt broke off i'd be SOL and pissed! Sometimes the DIY frustration is just not worth it. This is the kind of job I'd rather drop the truck off and pay someone to do.
 
Montana, whats the power gain like?

Sorry for the delay. Between a newborn and a new job, my time has been tight lately.

As for power gain? Butt-dyno says it is impressive, but I can't really quantify it. Essentially everything your engine did before (idle, accelerate, etc) it does better now because the engine can really breathe. I really didn't think the original manifolds were that restrictive, but they must have been. I recommend doing it. These headers with a Gibson exhaust is perfect IMHO.
 
Very cool that these are finally on the market.

I sold my t4r after both my manifolds cracked and Toyota quotes me 5000 to repair them.

Traded the truck in on a 2013 Tacoma Limited but miss the V8 everyday.
 
Curious if one were to just cut off the air tubes if these would fit on an 03-04 4runner?.....anyone try?
 
Did anyone in Ontario get these. I have emissions due this year and it wont pass with cracked manifolds, so I am looking at getting them real soon.
 
Did anyone in Ontario get these. I have emissions due this year and it wont pass with cracked manifolds, so I am looking at getting them real soon.

Not yet. I just did my Cat Back... still have a slight tick at Start-up from what I also think is a cracked header as well. Not up for emissions for another year or so though. I get code P0430 every 6 weeks or so, but when I clear it it stays away for a while. Would this help you pass? Rear Sensor Simulator - Underdog Racing Development
 

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