I decided to replace my downpipe today (both midpipe and downpipe) and was surprised to see what I would guess is the EGR valve hose running into the cat on the midpipe. What should I do with this hose? (it was welded onto the factory pipe) Should I try and drill a hole in my new midpipe and route it into the exhaust system? The only thing people discuss is the 02 sensor and no one seems to mention this other connector in the exhaust system. Any advise would be appreciated!

 

That is the split-air feed -- the air pump supplies air to feed the stock cat for emissions. You can remove it and block it off.

 

Great! I appreciate the advice. Another huge problem though... I just got the downpipe, midpipe, and a type B REDOM (Amemiya) ECU ordered off ebay used installed. When I tried to start the car, it sputters and then dies. Any ideas?

 

I plugged back in the factory 02 sensor and the stock ecu. I got it to start and finally get down to a 1500 rpm idle. I then installed the new ecu and started the car. The first few times, it died, so I kept cranking it and got it to start. When it starts, it idles between 2500 and 3000 rpm! The check engine light is also on.