How to: 00-04 headers onto 05-06 motor

Don't.

It's not for the faint of heart, you will have to tap your cylinder heads for plugs. If your Secondary Air Injection System (SAIS) is working, just spend the extra money and buy the correct headers. Or if your SAIS is dead and you already have the Hewitt bypass, buy headers from Dirty Deeds after talking with Keith. They offer a bolt on solution. But if for some reason you obtained a really cheap set of 00-04 headers, or bought the last ever set of Stan's Try-Y's before doing thorough research, and are determined to make them fit read on...

I accept no liability if you decide to do this. I'm a moron and only time will tell if my half-assed approach is reliable. At any rate this could all be returned back to factory should the need arise.

This thread contains some detail of the SAIS system and what separates headers of the two motors. When I first purchased my 00-04 headers from Stan's I incorrectly assumed the air injection ports were in the manifold, like many other manufacturers. Nope. Toyota plumbs the SAIS system directly into the heads. Hopefully someone else out there can learn from my mistakes. There wasn't a dedicated thread to this issue when my parts list was purchased.

Here is the difference between the 00-04 header flange and the 05-06. You can see the air injection ports. The top header in the photo is for the 00-04. Bottom header is the 05-06. This is the main hurdle that must be overcome to install these. Otherwise you will have a serious exhaust leak.



Pictured below are the Dirty Deeds headers posted by forum member FrenchToasty. These show the JBA headers with the 05-06 exhaust flange installed with the SAIS ports puddle welded to seal them. Lots of forum members have gone this route.



There are other how-to guides in this forum for installing headers. For a step by step guide do a forum search. I followed the same steps. Remove your cats, unplug o2 sensors, remove heat shields around the factory manifolds, disconnect SAIS piping, then undo your 8 manifold bolts. Only exception I did was remove the motor mounts to get easier access for the remove/install.

Pictured below is the SAIS piping on the factory manifold. Circled is where Hewitt instructions say to install their bypass plate.



Pictured below is the other end of the SAIS piping where it terminates at the pump under the intake manifold. This is where I will be installing the Hewitt block off plate after the piping is removed.



After your header is removed you will see the exhaust ports that share the same shape and size as the 00-04 cylinder head. At the 12 o'clock position is the SAIS injection port in the cylinder head. My borescope didn't save the images I took inside the cylinder head but the SAIS injection hole is a straight shot into the head then turns 45* to where the two exhaust valves merge together. I'll try to take pictures from the borescope and upload them tomorrow.



I had originally purchased some 1/4"NPT hex head aluminum plugs, but they were purchased before removing the headers so the SAIS port size was unknown. Taking measurements with calipers the opening is around 8.5mm. Quick run down to Ace Hardware and picked up some 3/8" hex plugs with an outer diameter of around 9.1mm, and a 3/8" course thread tap.




Now for the sketchy part. You shouldn't need to drill out your heads, it would be difficult to fit a drill into your engine bay and could only reasonably be done with your engine on a stand. The 3/8" tap is just the right size to cut thread into the SAIS injection port on the head without needing to be drilled. I stuffed some shop towels into the exhaust ports to prevent shavings from falling into the head and possibly combustion chamber. Coat your tap with grease to collect as many metal filings as possible. You can see how having the grease on the tap will trap a large amount of the filings as the threads are cut. Try and keep your tap as level and square as possible during this step. I'm not certain how thick the casting is but having oil from the head leak into the exhaust, or exhaust gases enter into your crank case would not be fun. I ran my tap so only about the first 3/8" - 1/2" was threaded. This will allow some of the plug to protrude out of the head.






My original plan of using aluminum plugs was due to the heads being aluminum. I wanted a plug that would expand and contract at about the same rate as the surrounding metal to help prevent exhaust leaks or the plugs walking out. That being said, my last minute run to Ace Hardware only resulted with steel plugs. Later in this thread you will see the plugs are still easily accessible with the headers installed. So if one were to back out or if I can find some aluminum 3/8" plugs I can always put them in later. But I was able to secure some ultra-high temp medium strength thread locker from an online retailer. The thread locker is designed to be used on rifle and pistol suppressors.



Prior to installing the plugs clean the grease from the tap off the SAIS ports, then use a shop vac to pull anything else that may have dropped down. Put a drop or two of the thread locker on the very start of the plugs, only the first half of the plug will be in the head. Start the plug by hand, then turn it the rest of the way in with a socket wrench. Just make it nice and snug, this is an aluminum head after all. This shows what the driver's side head looks like after the plugs are installed.





Now with the header installed you can see the 00-04 header flange still leaves the SAIS port plugs accessible should one ever fall out, or when I put in aluminum plugs. Also, as a nice bonus it looks like should I ever want to put 05-06 headers on I can just remove the plugs and the exhaust should still seal up.



This process took most of the day due to documenting and run to the hardware store. Doing this process now that the trail has been blazed shouldn't take but an hour or so longer than the normal header install. I'll post more info tomorrow how the Hewitt block off plate install in the new location goes and also upload bore scope photos of the SAIS injection ports in the exhaust port.

 

I would've bought the headers from you to save you that headache

 

I figured there was a way to do it. And I wanted Tri-Y's dammit. Hahaha

 

@empty_lord rubs his palms

 

I ain’t willing to tap my heads unless my motors out.

 

That takes you all of 30 minutes, we know it

 

There was enough room on the driver's side with the motor mount out to turn a T-handle. Easy peasy.

 

Oh I’m sure there is. I’m just not willing to do it unless I’m also doing other fun things lol

 

Yea going to be honest that's a little risky but now we know what it takes.

 

Would it be possible, if going this route, to remove all of the SAIS system? Or would it throw codes?

 

How many hp/tq will be expected to gain with the aftermarket headers?

 

After the break in and ECU self learn period I will be taking it to the dyno. I made another thread that showed my truck makes 248hp/278tq in nearly stock form. Realistically expecting only 10-15hp gain.

 

Good question. Hewitt offers a wide range of SAIS delete/bypass options. I would imagine there could be a way to completely remove the system with enough electronic gizmos. There is more to the SAIS than just a couple pipes and pumps. This is why Hewitt offers so many SAIS bypass options.

This header installation pertains to the actual air injection portion of the SAIS. Removal of injection lines and blocking the pump with a Hewitt Gen 1 kit in place.

 

Spent a couple hours today finishing the passenger side. Still haven't gotten around to installing the Hewitt bypass plates in the new location. Took a couple pictures of the SAIS ports in the head. You can see it goes straight in level with the ground about 40-50mm then blends into the exhaust port at a 45* angle.

 

Obligatory up-skirt money shot.

 

Looking forward to seeing the rest.

 

It's a shame they don't make these headers anymore. Really well built, the collectors are smooth, O2 sensor locations well thought out and accesible, no need for o2 harness extensions, was able to install them at stock ride height, and they fit with room to spare. Only really had to bend the parking brake cable support bracket just to make sure it didn't rest on it, that was it.

Depending on my work load this week I may or may not do the Hewitt block-off plates before taking the truck to the muffler shop. I'll keep posting here even on in the future to update if this install holds up. There will be a separate thread for the dyno results.

 

Found a few minutes of free time to drop off the truck at a local muffler shop today. I don't recommend driving with just open headers very far. About deafened everyone in a 5 mile radius. Sure my neighbors are cursing my name.

Getting installed are dual 2.5" Magnaflow cats, 2.5" Y-pipe, single 16" long 2.5" Borla muffler exiting on passenger side with a black 3" tip. Goal is to keep it quiet for long road trips but still hear it when you romp the throttle. I'm older with young kids so loud isn't appealing to me.

Still haven't found the time to install the Hewitt plates. I'll update then.

 

What magna cats and y pipe are you using? Was thinking in doing the same but wasn't sure if it would be cheaper to get a full system from Deeds.

 

Can't say for certain the part number of the Magnaflow cats. I told the muffler shop my specifications and they're piecing it together and welding it up. Only thing I know is they're 2.5" ID Magnaflows with the o2 sensor bung in the center. The y-pipe is being fabricated onsite, not an off the shelf item. I'll post pictures of the system as best I can when it's done.

If the invoice includes part numbers I will list them.

 

Thank you not sure if you would like to disclose the information but how much is the exhaust shop charging you?

 

Dirty Deeds quoted me $590 for catted mid pipes that bolt on between their JBA headers and the factory Y-pipe when I was shopping around. Not a bad price for header compatible bolt on stuff.

 

For all custom exhaust from the headers back, 2 cats, hand built y-pipe, muffler, exhaust tip, and all the piping it's going to be around $1,100.

Granted the piping is crush bent galvanized steel. Mandrel bent stainless would have been a lot more. I know the muffler is stainless, not 100% sure about the cats.

Stainless will usually last the life of the vehicle, and mandrel bends flow smoother. And a lot mid to high price range aftermarket exhaust kits are stainless with mandrel bends. I'm getting a custom exhaust to my specification for the price of some bolt on kits.

 

I’m still deciding on my setup when I go with long tubes. But mufflers with built in cut outs are a must and mandrel bends 2.5” from the header back.



really want to see if a mustang brola crossfire x pipe would make it sound interesting.

 

I've always wondered why no one ran an x or h pipe. Sports car thing?

 

I'm still all screwed up also I was going to go with JBA long tubes, Spintech 6000 and use Magnaflow cats and y pipe. Then have an exhaust shop fab the piping. But then thinking in going with a full system from Deeds but that like $2800


Spintech Prostreet 6000 muffler 2.5 center inlet/outlet
https://spintechmufflers.com/6000-pro-street/

Magnaflow 2.5 Y pipe
https://www.magnaflow.com/products/10768-custom-builder-parts-y-pipe

Magnaflow 2.5 cat
https://www.summitracing.com/parts/mpe-53006

 

I was going to go dual in/out 2.5" Borla with an X-pipe but that cost quite a bit more. Also worried about it being too loud. I've heard the benefits of X pipes, not certain why nobody runs them in the Tundras. Maybe the X pipe does better on an OHV engine vs our DOHCs?

 

Anyone ever try 2.5 dual in and single out and don't use a y pipe?

https://www.summitracing.com/parts/flo-8425453

 

Good idea.

 

That hurts