O2 sensor, laser power chip and a fast idle.

[Delpel]

I have discussed a problem previously with my BCR and the intermittent high idle speed.

The basics are that every now and again the idle speed goes up to 2000 rpm and then returns to normal after a few minutes/miles. I am also getting a lot of popping when I roll of the throttle.

I have recently changed out the catalytic converter and fitted a Laser Y- piece (with Lambda sensor fitted) and also installed a K&N air filter.

Today I took the bike to the only BMW dealer on island and had it hooked up to the computer. All was well apart from the O2 Sensor which was swinging above and below the recommended parameters. On the screen the sine wave generated was very cyclic and repeated itself. The dealer suggested I take the bike to their main workshop for some more tests on the O2 sensor as the computer instructed - marvellous this technology thing.

Could this be the cause of my problem of the increased idle speed?

I have also just purchased a Laser power chip. Should I wait and just install the chip as I believe it dispenses with the O2 sensor.

Your thoughts would be greatly appreciated as I am running out of hair to pull out.

[stempy]

Easiest way to check if it's causing the problem is to unplug it.

[Delpel]

If I just unplugged it, what can I expect engine running wise.

Does the Laser chip still need the O2 sensor in place or am I just getting paranoid.

[stempy]

The engine will run ok without the O2 sensor connected, though it will return a fault code to the ECU. It may run a little richer than standard. When I spoke to Gertjan at Laser he said that it was possible to run with or without the sensor. Basically, I think the sensor is ignored for much of the time by the ECU and only comes into effect after a predetermined period of constant throttle angle.

[Delpel]

I have spoken to Foster Rad on the Pelican site. Upon his advice I thought F*&k it - in for a penny, in for a pound. So with the thought of my warrenty going down the swany I installed the Laser power chip. Fired her up and the first thing I noticed was the shocked look on my face reflect in the left hand mirror

Then I noticed the wobbling of the whole front end at tick over has gone. Took her out for a thrash and there is definetly a different bike between my legs. Picks up quicker and I found myself slowing down on a road I don't normally speed on. The popping on over run has dissappeared as well. I still have the K&N air filter to put back in. Will do a spark plug check at some point as well.

All in all, one happy chappy.