I didn't think was a certain tubular manifold for 1g and 2g, the manifold has nothing to do with your exhaust lining up,now if was a evo 3 o2 housing your downpipe would be different lining up, the o2 housing is what connects the exhaust

Usatuff said:

OK I have a 1990 1g TSi. I've been looking around trying to upgrade to a 16g. I finally found a MHI B16g with a ported 2g tubular manifold. Now I also have a true 3" turbo back exhaust currently installed on my car. I know a 2g manifold will fit on a 1g, I think but will I have to do anything with the exhaust? It looks as if the turbo flange is closer to the passenger side of the car on a 2g then compared to a 1g? Any info is great, thanks!

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It will bolt right on to your 1g without any issues. I have read some threads about having to trim the drivers side corner of the 2g manifold for it to fix on a 1g but mine bolted right on. I have a 2g manifold on my 1g with a FULL 3" exhaust and too and it works great. Just to clarify though, the stock 2g manifold is cast, not tubular.

Sorry I'm retarded haha. It's a 2g manifold but it's not the stock manifold, some aftermarket name, MHI B16g with a 1g o2 housing.. Or would I be able to take the o2 housing I have on my 14b? Its already fitted for my 3" exhaust.

Usatuff said:

Sorry I'm retarded haha. It's a 2g manifold but it's not the stock manifold, some aftermarket name, MHI B16g with a 1g o2 housing.. Or would I be able to take the o2 housing I have on my 14b? Its already fitted for my 3" exhaust.

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Well since the flanges are the same, most aftermarket manifolds are not divided between 1g and 2g, I think that's why you confused us.

I don't know what o2 housing you have on your 14b. The stock 14b o2 housing and the 1g o2 housing are the same thing since the 14b came on 1gs. You can use either a 1g or a 2g o2 housing or an aftermarket tubular o2 housing (or you can even use an EVOIII o2 housing but you might have to modify the downpipe since it attaches at a different angle).

Hope this helps!

9!'clipseDOHC said:

Well since the flanges are the same, most aftermarket manifolds are not divided between 1g and 2g, I think that's why you confused us.

I don't know what o2 housing you have on your 14b. The stock 14b o2 housing and the 1g o2 housing are the same thing since the 14b came on 1gs. You can use either a 1g or a 2g o2 housing or an aftermarket tubular o2 housing (or you can even use an EVOIII o2 housing but you might have to modify the downpipe since it attaches at a different angle).

Hope this helps!

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Yea sorry I'm not that great at explaining. It's just listed as a "2g tubular manifold" And I was not sure if there was a difference. I heard some people have had to grind a little piece of it down or this and that but nothing major. If I can get away with using the o2 housing I have now then I'll just use it and maybe port it out a little. Thanks it helped a lot!