Y pipe

[bernsmartco]

The combined wisdom of the board distilled into a single thread.
Thank you all (to numerous to name individually) for your previous input most of it worked for me.

Why?
Improves the mid range performance
Cheaper than a replacement cat from BMW

Who make them?
LASER
ZACH
REMUS
Vanderlinde
Wunderlich Y pipe

Try Boxer Design for the Zach Y pipe much cheaper than (motorworks circa £200 nov 2004) [url]http://www.boxer-design.de/en/index.htm

Comments
Zach Y piece is best
Zack Y pieces are in two sections which makes it easier to fit The Lamba probe is also in a more sensible position which avoids re-routing and wires
There IS without doubt more power in the mid range
Zach pipe is a great mod and definitely better than the Lazer mid piece IMHO

Before starting:
equip yourself with 4 new stainless headers bolts since the ones holding the header pipes to the cat will probably shear... Start spraying your cat bolts with plus gas a little at a time a week or so before you try and remove them.
Don’t even think about doing it if the fuel tank is full.

fitting proceedure:
Do not take off the rear side panels/tail light/grab handle or seat.
Take off number plate holder, 3 small hex bolts hold on the number plate light panel, giving you access to two of the three bolts holding the number plate bracket to the cans, take out back wheel(did not need to remove the back wheel at all), remove/loosen nuts and bolts from exhaust system only; working from the back end forward, remove silencer first, no need to undo anything upstream from the cat bolts - which all broke off!
Gentle tapping brought the silencer unit out. Watch it does not land on the hugger and make sure the gromit holding the wire for the light is pushed out before it come off the pegs.
Had to twat my cans with a big rubber mallet
Cat came out after I found the 10MM bolts underneath it and the Lambda undid with adjustables. Unplug the 02 sniffer before you can wrench it off the cat with a 22mm spanner.
There's no need to remove the tank, just undo the securing bolts on either side, lift it up and prop it with a bit of wood.
The sensor plug is cable tied to the frame on the R/H side. The wire pulls out quite easily, just make sure when you put it back it follows the original route if it’s a zach pipe or the probe is in roughly the same place as on the cat.
Ha bloody ha you must have the fingers of a five year old if you can get in there to undo that plug. The tank needs to come off and make sure you have something to drain the fuel in to.
Laser requires you to free up the hidden lengths of cable for the lambda probe, to fit it in the odd new location on the Laser pipe.
One person reported needing to cut the pipe that goes into the back of the cans a bit to make sure they go completely onto the two pegs underneath the seat.

Watch you don’t push the bike off its centre stand as you try to push the cans back on. If you are fitting the original cans to a laser pipe remove the spacer in the pipe clip to give a tight grip.(will they ever come off again?)
Everything went back with a rich coating of copper grease, reused the metal gaskets, preloaded the Lambda wires so they were at rest when the unit was secure. You need the wire out for fitting to a laser pipe because its not long enough to go back in the original position. Make sure its not chaffing anywhere when you re-route it.

Anything I have missed?

[oyster]

Brilliant!
Anyone doing a cat removal should print this off and read it at least twelve times while looking at the bike! Then start but only after arming with all the required suggested items. Otherwise you may find yourself needing bolts/copperslip and no transport to get them!

N.B. Wunderlich and Remus Y pipes must be almost identical to the Laser two piece pipe, so same applies.
Definite low/mid power improvement, never tried full bore enough to prove that area!

[Archie]

Gentle tapping brought the silencer unit out. Watch it does not land on the hugger and make sure the gromit holding the wire for the light is pushed out before it come off the pegs.
Had to twat my cans with a big rubber mallet

After failing to get my cans to shift I found that if I pushed the front of the cans hard against the seat, I could just get a shot of WD40 to hit the mounting rubbers. The cans then magically slid off.