dfj240

iTrader: (1)

Based on a lengthy search that yielded me no answers, I figured I would turn to you lot for the answer, should anyone know it. I need to replace the headers on my 02 Maxima 6-Speed, because I believe the pre-cat(s) to be clogged. Is it possible to bolt up just a set of aftermarket headers to the factory y-pipe?

In my search I noticed that several people were able to bolt an aftermarket (warpspeed, etc.) y-pipe to the factory manifolds, but I wasn't able to find anyone who had bolted aftermarket headers to the stock y-pipe.

Even more specifically, I have a good friend who is an aftermarket parts dealer, and can order me some headers for the 3.5 Altima, but none of his suppliers carry headers for the Maxima. Would the 3.5 Altima headers bolt up to the factory Y-pipe?

Thanks, and my apologies if this is a "noob" question, but I couldn't sort it out with google or the .org's search function. Cheers.

-Nathan

TL;DR = Will aftermarket headers bolt up to the factory Y-Pipe?

Edit: Oh, and I know the Altima headers don't work because the Y-pipe supplied with the Altima kit doesn't clear the cross member. That's why I'm curious about possibly using the factory Y.

cjandura

iTrader: (3)

You just need to replace your precats they are not one solid piece with the exhaust manifolds and i doubt the cast iron has rusted thru unless the car was sitting in the ocean.

dfj240

iTrader: (1)

Yes, but I have no intention of spending the money on new pre-cats that are just going to fail again in the future, or disintegrate and suck bits of catalyst into my engine block and score my cylinders forcing me to rebuild or buy a new engine. If I'm going through the trouble, I would rather just dispose of them entirely, so that I never have to worry about them ever again.

Beside the fact that new pre-cats are even more expensive than Cattman headers that include a Y-pipe($567 each! Cause I certainly don't see the merit in replacing old pre-cats with old pre-cats.).

If I can't find a suitable new set of headers, or compilation equal to such, I will probably just remove the pre-cats and hollow them both out completely. Again, I'm not particularly worried about the performance gain, as much as unclogging my exhaust so my car will run properly, and getting rid of one of my worst automotive enemies (the pre-cat).

I've already had a pre-cat disintegrate and suck itself back into the motor of my 2002 Toyota MR2, and I was not pleased that I had to replace an engine that only had 58,000 miles on it when that happened. I'm not fond of having it happen again.

-Nathan

L_U_D_I_AMaxima

iTrader: (3)

simple solution... take the cats out gut every single piece of the actual cat from the inside, put new gaskets and go on with your life until you safe money for aftermarket parts...

dfj240

iTrader: (1)

I've got the money for aftermarket parts, I just don't care to spend Cattman money on this car, since this car is for hauling the kids/wife around in. I would like for the majority of my aftermarket parts fund to go towards my toy rather than my grocery getter. At the same time, I don't really care to go through the pain of gutting my precats if I can buy a set of Altima headers for as inexpensive as they are, and just slap them on and be done with it. I gutted the precats of the aforementioned MR2 Spyder before I installed the new engine and it was a PITA, and I wish I had just bought a header for it.

In short, I would rather install some headers onto my factory Y-pipe and call it a job well done, than go through the time consuming PITA that is gutting precats. So if the Altima headers will bolt to my stock y-pipe without much fuss, I'll be a happy man, and go for it.

If no one knows, then I'll probably fork over the cost for the headers, and give it a go. If they don't bolt straight up, then I'll figure out exactly how to modify the setup to work, document the whole thing, post on here, and listen to every one whine about how I wasted my time and money and should have bought Cattman's.

If someone knows for sure that they absolutely, 100% won't work, then I'll cease and desist, and carry on with my original plan of locating some OBX headers, or gutting the pre-cats.

-Nathan

OnOiShNo0dl3Z

iTrader: (2)

I believe the altima shorty headers don't bolt on to the 5.5 gen maxima, but you might want to have someone else confirm that.

If you get OBX, just know fitment usually requires some slight modification.

Cattman usually bolts right on just fine.

NmexMAX

iTrader: (22)

I don't believe anyone has done this on the 5.5 gen, and if they have, they haven't posted much info on it.

But the 4th gen, 5th gen and 5.5 are similar enough in this department that I would say it's the same general principle albeit a few quirks here and there.

http://forums.maxima.org/all-motor/6...-knockoff.html

Brl24

Honestly man, if you think gutting the pre cats is a pain, you won't be just "slapping on" headers. I have gutted pre's and a cattman y, which perform quite well.

Getting the pre cats off may be a bit of a pain but the removing whole manifold is pretty sh*tty from what Ive read.

If you don't want to spend much and arent going for major hp, drop the cats(the hard part) and gut em which is pretty easy. If your stock y is still in good shape you can keep that, or go for an aftermarket one which you can get for pretty cheap and will give a bit more hp.

dfj240

iTrader: (1)

Well, I'm about to pay for some Altima 3.5 Headers, and see what has to be done to get them to mount to the factory Y-pipe. I don't think they will just bolt right up, but we are going to see. In my own (albeit probably deluded) imagination, it should be more of a flange relocation than a complete custom fabrication of all of it. The goal is going to be to get the Altima headers to bolt up to the stock 5.5 gen Y-pipe with as little modification as possible.

I have more interest in spending a little money on these headers and spending my time and effort doing something (apparently) no one has tried before, than spending my time pulling apart an old rusty manifold just to clean it out and bolt it back up. I think I would feel more accomplished by it, and I'll be providing some good information for anyone here who might share my same thoughts and sentiments.

I know that I will spend money making it work with the factory y-pipe, but as cheap as I'm getting these headers, I will probably barely spend more than a set of OBX's would cost, if I even get THERE. Will it make as much power? No way. Will it be simpler than bolting up some Cattman's? Not by a long shot. But it will a good cost effective way to get rid of some pre-cats, while setting myself up with a half-decent header setup if I ever decide I want to squeeze a bit more power out of her.

Anyways, enough of that. I'll post a thread/write-up/how-to when I get these sorted out and installed. Won't know if it works until someone tries right?

-Nathan

AznRyan

iTrader: (1)

Correct me if I'm wrong, but isn't the engine mounted differently in the altima, as opposed to the maxima?

andrewmac

iTrader: (2)

Sorry to hijack your thread but I have a question related to this. I bought a neglected maxima for cheap and I'm currently in the process of breathing new life into it. I have the engine out now just waiting on a new one since the old one is shot. Anyway, the exhaust is completely rusted to ****. There isn't a non-rusted spot on the entire thing from front to back. Rest of the car is in good shape but the whole y-pipe, precats, etc is all covered in rust and the car has 280,000kms on it.

After reading this thread it has me worried about the pre-cats.. is the risk really as great as OP is saying? Can you really ruin a good engine with some bad precats? Is it luck of the draw or gradually happens over time? Now I'm worried I'm going to put the thing back together and suck crap from the precat into my new engine.

ShocknAwe

iTrader: (3)

No your not going to do that. Don't worry about it

NmexMAX

iTrader: (22)

Uuuggghhhh. Why not take a look at the thread I linked. I think you might be over thinking this.

IMO, the link I provided is the best you can do.

It be worse trying to complicate things trying to get those headers to your OEM Y-pipe, if these are the HS sort of replicates, that's not going to happen very easily and the level of work and difficulty will, in the end, not be worth your time, since as was mentioned before, gutting is probably the easiest way and most cost effective method.

No, it's identical, the only difference that was mentioned before is the subframe mounting. The Altima is far more similar to the 04-08 Maxima.

Seems like a no brainer, but depending on budget and ultimate plans for the thing, either gut them or get some headers and be done with it.

dfj240

iTrader: (1)

Well, I've read through that thread, multiple times. In fact, I've got it up still on another tab, and I've been pouring over it repeatedly. You're probably right though, if I'm honest. I'm probably over thinking this. I haven't slept all night. This thing being down for the count has left me stranded in TX, while my pregnant wife and my daughter are back at the house wondering when Dad's going to be home. So, I'm anxious to get back, but I also want to take the best route possible.

So, in other words, you're saying that, if I try to go this Altima headers to factory y-pipe route, I'm just being daft, and that I'd be better off smashing my head repeatedly with a hammer, and I should just gut my pre-cats, and forget it altogether?

-Nathan

NmexMAX

iTrader: (22)

http://forums.maxima.org/all-motor/6...-knockoff.html

Brl24

Ya Nathan, if your willing to remove the stock mani's to put headers on, you might as well save the money, drop the cats and gut em, and they will bolt right back up. This is gonna be way easier than removing the actual mani's, will protect from any cat material getting in the engine and you don't have to cut or weld any of the parts.

You will get a bit better exhaust flow, and if you want you can get an aftermarket y pipe down the road, and it will bolt right up.

dfj240

iTrader: (1)

Fair enough. You're right. Once again, lack of sleep, and being away from wife and daughter makes this quite a stressful situation in which I am probably not thinking as clearly as I should be. Thanks for the brain power assistance. Lol. Cheers.

-Nathan