JDM 02 Sensor Housing/Exhaust Question

[got_no_sol]

Ok so I bought the jdm engine and it has the 16g but the O2 sensor housing that came with it is too big too bolt up to the stock exhaust (see attached photos).

We ended up using the t25 o2 sensor housing just to get it running for now, but the holes for wastegate etc do not line up.

I know I need to replace this but for now I just want to get the car running. Where can I find the o2 sensor to turbo gasket for that 16g? just the gasket by itself!

from measuring it quickly I found that the stock (usdm t25) downpipe/o2 sensor housing is 2 inches while the jdm (16g) is 2.5 inches.

So I assume a 2.5 inch downpipe would bolt right up right?

But if i'm going to replace the downpipe anyways I would want to get 3inches ALL THE WAY back - How do I make a 3inch downpipe fit on a 2.5inch o2 sensor housing?

The JDM o2 sensor housing -

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And of course the Stock Downpipe -

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Do I have to just get a 2.5inch downpipe to make this work?
And if i want to go 3 inches all the way do i have to get a new o2 sensor housing?

Thanks! and sorry if this doesn't make much sense - it's been a long day!

 

[rowlex]

Have you tried test fitting it on??? If you have, what doesn't line up?? If it's just the bolt holes bring it over and you can use my die grinder, I also am going to attempt cutting the gasket I have for my t-25 with the die grinder (to expand the ports)

You could also get the megan racing 3" SS DP it should bolt right up to that o2 housing (since its inlet is also ~+2.5") I got mine for 160$ shipped

 

[got_no_sol]

basically, the jdm o2 sensor housing bolts directly up to the 16g - obviously since that's what it came off of , but it's opening to the downpipe is 2.5 inches whereas my stock downpipe is 2 inches....

Another problem - the jdm sensor plug is a two wire line with a different style plug while the the usdm is a 4 wire sensor with a different style plug - so I need to replace the 02 sensor in the jdm housing, but in order to do that i have to buy a new one
is this a dealer part?

or there are any other options?