EJ22 - borla exhaust header; dual port or single port

[EJ22_SLO]

I have 1990 Legacy EJ22, wagon, 4wd, manual 5 spd.

My stock exhaust header is worn out - old and rusty... welding it doesn't help anymore... so i have to buy new one;
Subaru header (with cat) costs ~800 USD; borla costs ~350USD + custom, tax (~22%)...

As far as I know 2.5 header fits 2.2;
I'm looking at Borla 2005 catalog - they offer:
Forester: 2.2L/2.5L 4CYL MT & Dual Port Cylinder Head Only 97-04 Header part # 17183


Impreza: 2.2L 4CYL AWD 2DR/4DR/WAGON Single Port Cylinder Head Only 96-04 Header Part# 17199


What's the difference between dual and single port? Is it only the separated piping... 1-2-4 with fisrt one and 2-4 with second one? What to choose? Would both fit? Where to buy (online)?

[vrg3]

Some Subaru cylinder heads have two exhaust ports on each side, and some have just one. You need the header to match up.

Your wagon needs a dual-port header.

[EJ22_SLO]

Thnx for info.

Q2: Will it fit? ...since passenger side is curved arround front side of the engine; stock is kinnda "Y" shaped...

Q3: Any suggestions or alternatives for some other manufacturer (i want unequal length)?

[vrg3]

As long as it's meant for a dual-port non-turbo EJ engine, it should fit at the front. But, I don't know if it will bolt directly up to your existing exhaust; you may have to do a little bit of custom work.

[EJ22_SLO]

Yup, I know i'll have to change/rebuilt the rest of exhaust (move the cat,...); but i think it should bolt on directly onto cyl. heads;
the reason i asked if it will fit, is because of the "bend" in front of the engine... i'll propably have to remove the engine "protection" below the oil pan (dictionary says "sump");
it's N/A EJ22; 270.000 km; in pretty good shape; some problems with exhaust gas leaking into water system near thermostat at high load - it makes air pockets, thermostat closes and leaking gas pressure forces the cooling water out; happened to me twice; leveling the cyl. heads should solve the problem

[BAC5.2]

It should bolt up to the stock exhaust.

[belladonna]

yes, you will have to remove that plate that covers your pan...it will make changing your oil filter a little more hard because it sits close to the filter, but other than that, i haven't had any problems with mine...installation was easy...

[EJ22_SLO]

thnx for first hand info belladona; pictures on your cardomain site helped a lot. Do you know the diameter of the piping at the end of header?