[07wrxguy]

can i put my stock exhaust on with my aftermarket downpipe? in other word do i have to have an aftermarket cat back to support the dp? also is there any difference in pipe size between the wrx and sti stock exhaust?

 

[Sasquatch]

The short answer: yes. As far as the fitment it depends on the manufacturer. I have the Cobb TBE - it is compatible with the OEM CB.

 

[07wrxguy]

what other dp are compatible with the stock exhaust?

 

[Sasquatch]

what other dp are compatible with the stock exhaust?

Most aftermarket systems are 3" in diameter. Look for those that taper to 2.5". I cannot think of any of them top of my head. I know Invidia are quite popular - not sure of the taper.

 

[Sasquatch]

The stock and Cobb DP:

 

[07wrxguy]

so the downdipe has to taper to 2.5 to make it compatible with the stcok exhaust

 

[Sasquatch]

so the downdipe has to taper to 2.5 to make it compatible with the stcok exhaust

Correct. The angle of the image does not show the taper very well.

 

[07wrxguy]

thank you kindly

 

[Sasquatch]

You are welcome.

I would expect more responses from those who have first hand knowledge of other DPs that taper to 2.5".

 

[07wrxguy]

thanks for that pic. heyt where is the bung for the o2 sensor on the cobb. i dont see it

 

[Sasquatch]

Take a look at the shadow from the Cobb just before the outlet. You can the very top of the fitting as well.