Doug Thorley Headers

[Jayman]

this is what I got from Steeevo about headers for the SC version when I asked him if they were at least compatible with the SC version:

Unfortuanately these Long tube headers are for the 2000 - 2004 non-supercharged Nissan 3.3L V6
There has been quite a bit of interest in the SC version and i'll be bringing this up to Doug Thorley. Hopefully they will make something available for you guys.

Steven Lutz "SteeevO"

[Big Bird]

Ive compared prices to A/C. Its only a $80 USD difference. Plus A/C has them in stock, so there is no pre-order.

[steelcityslicker]

Both seem to replace the first set of cats. The Doug Thorley's are being labelled as "long tube" so I'm assuming you will get the benefits of long tube headers (whether or not that helps with the 3.3L I'm not sure?). The big difference and benefit that you get with the Thorley's is the ceramic coating inside/out, for less money over A/C's.

[Big Bird]

The only problem with both sets is the cost to install. Once installed you have to remove the cats, install two new ones further down. Remove the second ones and modify the 02 sensor. Which in the end will cost you about $500 bucks on top of the cost of the headers. Now lets just say you want to do your exhaust cat back. Thats another $600-$900 bucks. In the end yuor complete exhaust system will cost you around $2000.

[Jayman]

The only problem with both sets is the cost to install. Once installed you have to remove the cats, install two new ones further down. Remove the second ones and modify the 02 sensor. Which in the end will cost you about $500 bucks on top of the cost of the headers. Now lets just say you want to do your exhaust cat back. Thats another $600-$900 bucks. In the end yuor complete exhaust system will cost you around $2000.

Yes, it's an expensive endeavor if you are doing it all at once.

In my case, I already know that my D-side manifold is cracked, and that the cats on that side are shot as well. I also already have a Magnaflow cat back, so I'm doing some regular maintenance and upgrading at the same time.

That will save me at least some of the money there, and I always look for the excuse to upgrade anyways...

[steelcityslicker]

I want to run headers and a free flow exhaust. I guess i didn't realize just how much this would cost. So, it looks like I'll be purchasing mine a bit at a time and hopefully take advantage of some deals out there.

As for extending the O2 sensors. Would it be better to take the sensor somewhere else first ie; electrical shop so that they are done properly or will it matter?

[Big Bird]

Most likely I will be starting off with the exhaust cat back, once it rotts out or starts to leak a lot. Right now i am at 210,000 km's and the exhaust is looking good for original.

As for the 02 sensor wiring its not bad for you to do the work. Make sure you put a good soder on the wires and use the same gauge of wire. Dont forget shrink tube. The shrink tube I would reccomend is the one with the soder. As you heat up the soder inside the shrink tube will shrink and seal the soder. I will be using old 02 sensor wiring from defective sensors. The first two jobs will be exhaust (cat back) and wiring.

[Big Bird]

Well after ripping out the manifolds while doing the head gaskets I noticed the cracks. Not on the passenger side but on the driver side. I actually hear the leak more now coming from the manifold. Hopeflly it holds up for now. The engine runs great other then the fluttering noise from the driver side manifold.

[morb]

So why are there two part numbers on the ruggedrocks site?

Since my front cats are already punched out and running through highflow cats farther down it only makes sense to throw a set of these on....if he's selling them yet. That and the effin crack.

BTW what's with freakin Xterra's and manifold cracks at 100k?!? That's pretty rediculous and common enough to warrant a recall.

[Big Bird]

People have tried to put it even under a safety recall due to the fact that they would smell the fumes inside the cabin. Didn't go through.

[Nd4SpdSe]

Anyone have any information in regards to extending the 02 sensors? My DT headers should be in and I want to get them installed ASAP, which I might end up leaving my truck being and get them installed while I head back home to Ontario having the week of May24 off. I have 2 brand new 02 sensors waiting for this as well, but I'd personally like to extend them myself, but if I can't be there when they put them in, than get it do it before hand. Not that don't trust me cousin, but I know that how his forte, maybe his buddy is, but it being my truck, and something as critical as 02 sensors that are exposed to the elements and crap from off-roading, I'll have the piece of mind knowing it shouldn't have to do any trail repairs from the 02 sensors. Of course I don't want to make them abnormally long, but I dont want to have them too short either.

[Snafu]

I only had to extend the passenger side. The driver side was okay. Use good shrink tubing over the soldered joint.

Instead of extendind the wires on the O2 sensor, I extended the plug instead and used the stock wire length of the O2 sensor.

One trouble spot was the driver side front sensor. There was not enough room to pull the sensor out and I needed to make some clearance. Not an issue if you install the sensor on the header then install the header but it may be hard to replace the sensor later on. Test fit the headers and see if you have the clearance to install the O2.

Are you running the stock rear cats or customising? The stock pipe on the rear cat may need some tweaking to line up the header flange. The shop where I had it done did the tweaking.

[Nd4SpdSe]

Instead of extendind the wires on the O2 sensor, I extended the plug instead and used the stock wire length of the O2 sensor.

Do you remember or can you measure how much you extended it by? I'd rather extend the actual 02, which is a replaceable item, than touch the truck harness. Plus, I can do the soldering on a bench and do a perfect job, than try to work through the wheel well of a truck

One trouble spot was the driver side front sensor. There was not enough room to pull the sensor out and I needed to make some clearance. Not an issue if you install the sensor on the header then install the header but it may be hard to replace the sensor later on. Test fit the headers and see if you have the clearance to install the O2.

Ohh, good to know. Since I have new 02 sensors sitting in a box waiting to go, we'll just put them into the headers before hand. Not sure if a body lift would make it easier or less of an issue

Are you running the stock rear cats or customising? The stock pipe on the rear cat may need some tweaking to line up the header flange. The shop where I had it done did the tweaking.

Oddly enough, I remember looking and I remember not seeing a second set of cats...which I had found weird cause I remembered reading that the 00-01's were only suppose to have 2, and the 02-04's were suppose to have 4.

I got a 2.5" stainless catback done a year and a half ago. With the headers, I'll be going catless for a while, pending it doesn't drive me nuts. Fortunately I'm plated for Quebec, and it's a relatively common here it seems, and if I get caught, I've got 48 hours to fix it, so not the end of the world, online Ontario. With Quebec plates, I should be ok in Ontario. Unless someone can confirm otherwise, but I can't see the Ontario police having the ability to pull my plates, but they could still fine me. It'll save on the initial install cost, plus since there's no emission tests here, it would be a waste since they'll probably be no good by the time I'm in a place where I need to get them again

[Scotto]

I'm currently wrestling with the cat problem right now - just looking for a decent solution. I'm thinking I could put rear cats on it, and they should be good enough to pass emissions. Or, alternatively, put the stock exhaust back on every two years...

[Snafu]

Ohh, good to know. Since I have new 02 sensors sitting in a box waiting to go, we'll just put them into the headers before hand. Not sure if a body lift would make it easier or less of an issue

It should not be an issue until you go to replace the O2. I mentioned to Steve at RR that it would be better for the bung to move out slightly (~5-10 degrees) for clearance but not sure if he has done anything about it.

Do you remember or can you measure how much you extended it by? I'd rather extend the actual 02, which is a replaceable item, than touch the truck harness. Plus, I can do the soldering on a bench and do a perfect job, than try to work through the wheel well of a truck

I will have to measure it. I think we added about a foot (shop guys did it while I was wrestling with the driver side)

My 01 (built sept-00) had all four and FSM shows four. Check the FSM to see what should be there. If you have no cats then emissions could be a problem if done in Ontario (future testing in Ontario will be based on codes).

Check the cat-back system to see if reaches up to the headers. If it does then you are golden! My nismo cat-back system started where the second cats ended. So I had to use the pipe from the the end of the first cats to the end of the second cats. It needed massaging to fit properly to the headers (was not a direct bolt on like I thought it would)

@Scotto - drop by sometime and have a look at what was done on my truck. We re-used the pipe from the end of the front cats to the end of the second cats with some slicing and dicing to join the headers and cat-back. It is not ideal since the stock pipe is smaller than the headers and cat-back and I would have preferred to use a larger pipe with the stock cats.

I will be looking into this over the summer and see if I can get a better solution. What I think will be best is to move the rear cat as close to the header as possible and move the rear O2 behind the cat and use a larger pipe to match the rest of the exhaust. I might re-use the stock cats since they are working or might replace them ($500 more for the good cats).

I had the work done at CoachWorks in Milton. A great shop and good guys. They got the pipes, benders, hoists and welding needed.

[Nd4SpdSe]

I will have to measure it. I think we added about a foot (shop guys did it while I was wrestling with the driver side)

Gives me an idea. I want to go pick up some wire tonight as well as that special shrink-wrap that has the sealing glue inside to really seal it up.

If you have no cats then emissions could be a problem if done in Ontario (future testing in Ontario will be based on codes)

Of course. I perfer to run legal, but aftermarket cats don't last, and I'll be in Quebec for at least 2 years, so I'll run as i can for now, and if and when I get back to Ontario, she'll be back normal after.

Check the cat-back system to see if reaches up to the headers. If it does then you are golden! My nismo cat-back system started where the second cats ended. So I had to use the pipe from the the end of the first cats to the end of the second cats. It needed massaging to fit properly to the headers (was not a direct bolt on like I thought it would)

Actually they go right up to the (primary) cats, welded right to it. Me and my cousin don't like the direct T that goes from the passenger bank to the piping on the drivers side, so he want to redo that for better flow, and also, add flex pipes off so that the headers dont crack from the flex and vibration of a completely solid system.

[Snafu]

but aftermarket cats don't last,

From what I have heard there is a big difference in aftermarket cats out there. I held cheaper and better cats and there is a definite difference in weight due to the amount of the metals used in the cats. The cheaper ones may not even last a year

Save your OEM ones you pull off the truck. Unless they rattle bad inside they may come in handy down the road. If you can't store them then you can always drop them off at my place

Actually they go right up to the (primary) cats

That is good to hear. Less mucking about will be needed.