Interest in Custom built 4th gen V8 4.7 Doug Thorley Headers
- Thread starter brighton
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Bonyfattony
New member
The install was free from Doug Thorley Headers since I allowed them to use my car to build us headers.
I haven't noticed any drastic change to my MPG. I am going on a road trip over the holiday so that will be the best way for me to track and see if it has gone up or down.
I do not know how long the install was but I can check and get back to you.
Bonyfattony
New member
I made it back! I put about a 1000 miles on them and it seems little less to no change on MPG. For the most part, I am very satisfied with the headers. It felt much smoother on the road and have not ran into any issue or codes.
poncharello
New member
Be sure to let us Californians know whether or not you run into any issues when it comes time to get that bad boy smogged!
Does anyone if there are any differences to a Canadian 4runner? My exhaust manifold is cracked and the cat back is full of holes. I have been looking for these for a long time. I am surprised that they fit. I had a welder over at my place in the summer and he said there wasn't enough room for headers, but he would build me a new manifold that wouldn't crack. And two days ago, my truck started throwing F430 codes. Could it be related to my lousy exhaust?
rileyru
New member
Any updates?
Specifically, estimated install hours or dollars, or instructions?
Also above comment said "for the most part, I am very satisfied" with the headers, why not just very satisfied? Any negatives besides cost/install?
Love my 4runner but it is starting to tick on a cold start.
Specifically, estimated install hours or dollars, or instructions?
Also above comment said "for the most part, I am very satisfied" with the headers, why not just very satisfied? Any negatives besides cost/install?
Love my 4runner but it is starting to tick on a cold start.
TRDCal
New member
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:
zmyslowy.edek
New member
Hi,
did you see those?
Toyota Tundra / Sequioa 2000-2004 4.7L V8 2UZ-FE Stainless Steel Headers
Thay have emailed me, that should fit to 2004 4runner. I have them, I will post pics once I have them installed...
did you see those?
Toyota Tundra / Sequioa 2000-2004 4.7L V8 2UZ-FE Stainless Steel Headers
Thay have emailed me, that should fit to 2004 4runner. I have them, I will post pics once I have them installed...
You will have to get them fitted to clear your steering shaft on the drivers side, and your dipstick tube will need to be adjusted on the other side, but should be fine for the 03 and 04. For that price it's worth the fitment!
montana_jeepn
New member
Just pulled the trigger on a set of these. Once they arrive I will just need to find a shop to do the install. Pretty excited. 
montana_jeepn
New member
During the install, did you have to bypass your air pump?
montana_jeepn
New member
Heat deflector necessary or not on Thorley Headers
Looking forward to getting these headers for my 2005 Sport V8 VVTi 4.7L. I think the OEM headers have a heat deflector around them... is this a potential issue with Thorley headers??? Also, is there any 'how to' video out there where we could take the original headers off, with the cats; then take them with the new Thorley headers to a welding shop to have cats remounted on new headers?? Then put it back together.
Looking forward to getting these headers for my 2005 Sport V8 VVTi 4.7L. I think the OEM headers have a heat deflector around them... is this a potential issue with Thorley headers??? Also, is there any 'how to' video out there where we could take the original headers off, with the cats; then take them with the new Thorley headers to a welding shop to have cats remounted on new headers?? Then put it back together.
montana_jeepn
New member
First of all, I would like to thank [MENTION=750]Gadget[/MENTION] for recommending Jeff (The Muffler Shop of Maryland: Exhaust and Metal Fabrications, tel: 410 414 8164, Owner: Jeff Reinoehl aka-"Insane Jeff") to install my headers. This is not an easy install and I do not recommend doing it yourself.
Jeff has owned his own muffler shop for I think about 25 years (I recall this from reading some news paper clippings in his waiting room), does custom fabrication, and races his own drag car. That said, it took him and one of his techs 8 hrs non-stop (included welding in two stainless bungs for an A/F gauge and one on the other header for future sensor growth) to do this install.......he told me that a regular muffler shop would likely take 12-15 hrs if one dedicated tech was working on it. And looking at how tight it is, I believe him.......I happily forked over my money.
As for the heat shields, the headers don't have them. I have noticed that I am running 5-10 degrees hotter than I was before....so something to watch when summer comes. During the winter the benefit is that she warms up quicker. I currently average about 189 degrees.
I kept all four cats in place since I am still in the military and have no idea where I'll be stationed next and what the smog requirements will be.
Was it worth it? .......not cheap, and I have no dyno results to report (just butt-dyno), but I can tell you with no question that even with my oversized tires and stock gears, I will smoke a stock 4Runner no question.
She accelerates faster and is overall smoother. Good luck if you decide to give it a go yourself.
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