Well yesterday went and picked up a Two Brothers aluminum low mount exhaust (005-040606) for my '04 F4i. I'm sure many of you have this pipe on this board.

Went home all excited took the old exhaust off start to put the new one on.. then horror of horrors! There is no hole in the mid pipe to screw the O2 sensor into! This, despite the installation manual from Two Brothers states that the O2 sensor should be screwed into the mid pipe, or for non-California bikes, to use the supplied block off bolt and copper washer to seal the bung. Well, there isn't even a supplied block off bolt or copper washer either! WTF has happened to their quality control? [:@]

Anyway, right now I have the pipe installed without the O2 sensor, but the guy I bought it from has a drill and tap kit so he will probably help me put a tap in the mid pipe. Regardless I'm going to call up Two Brothers' office on Monday morning and try to sort things out.

The other issue was fitment. The space between the swingarm and the midpipe seems very tight. I'm not sure I installed everything correctly. I installed everything with the bike on a rear stand and nothing was touching, so I'm pretty sure that the rear was fully extended. Still, I'm a little nervous when those pieces are so close together... [&:]

 

You can buy an O2 sensor eliminator that is a plug and play wiring harness. I got one for my Micron. It was about $20 shipped.

 

i have always heard two brothers has horrible quality. my buddy had an rc51 and the baflling, or however you spell that word, started to come out after about 900 miles of regular street riding.

 

I don't want to pay $20 for something that should be part of the exhaust. Two Brothers should replace the middle pipe for me free of charge, because what I paid for and what was supposed to be in the box wasn't there.

Anyway, I ziptied the O2 sensor to the frame for now, and went for a ride. The sound is really nice, but the engine now idles at 1400, where it used to stay 1000-1100. This is probably due to the fact that the O2 sensor is getting a reading from the ambient environment rather than the exhaust fumes. Tomorrow I will try and have Two Brothers resolve this situation for me.

 

Hey dude, about the pipe being close to the swing arm: This is 100 percent normal ! So is mine. There's like 1 mm. airspace between the midpipe and and the swingarm on my set up. No problems whatsoever. When you sit on your bike it moves further a part. I couldn't be more happy with this pipe than any other I considered. Even though it's a slipon it gives you that little edge w/o loosing power as I considerd the Yoshimura RS3 slipon where you'd accutally loose about 3hp in the low range. Fix the 02 sensor problem you got and ride away. If I were you I'd have the pipe exchanged for the exact one you need w/ the 02 sensor I wouldn't dirll in a brand new pipe dude. You can see mine here.http://youtube.com/watch?v=yBCRrPqWzuA

 

I don't know if Two Bro's has that option of a drilled out midpipe like the stocker, but Micron didn't. If you ordered properly for the year of the bike, and they offer a drilled midpipe, I'd definately check with their customer service department. I was surprised, too, when I first got mine. I was like, "You sons-a-bitches sent me the wrong one", but the customer service guy said it was the right one, I just needed the eliminator. Good luck, bro.

 

two bros. definately should have sent you a midpipe pre-drilled for the 02 sensor. i too have a CA bike (but i live in MD). when i purchased mine it came w/ the pre-drilled midpipe and the cap/fitting to put into the whole if i didnt have a CA model.

also, rest assured........the midpipe is VERY close to the swingarm, but it appears thats how all of them are.

 

The midpipe is super close with my Two Bros exhaust as well. Oh well.

 

Well, this morning I called Two Brothers and talked to Brandon who was really cool about it. He told me they would swap out the midpipe for me free of charge.

As luck would have it, I happen to live about 10 miles from their facilities, so I went down there with my stuff this afternoon. It turned out that they no longer make that particular pipe anymore, so it would not be possible to simply swap the midpipe for the right one. Then this older dude (I didn't catch his name but he might be one of the owners) came and talked to me, and he was able to get one of their welders to drill the hole and weld the right piece on there. So I brought it home and reattached it and everything worked beautifully. I was in and out of Two Brothers' facilities in about 45 minutes. On top of that they were really cool about the whole thing. They could have been dicks and said that it's not their problem, and that I should take it up with the website that sold the pipe to me. Instead, they resolved the situation quickly. That's what I call customer service!

- A now happy customer.

 

awesome! glad to hear it got resolved. now you need to post up pics of the whole bike w/ the pipe on it!

you'll notice it sounds REEEEEEEEEALLY good between 4.5 and 5k rpms , although idk if the tone at certain rpms would be different on my pipe than yours.......i have the 10" shorty.