O2 sensor question

jmmccauley · jmmccauley's Garage

I have some issues with my 2004 Rhinewest chipped/Rhemus bike. We did some readings and the O2 sensor flat lines where as we check another bike and it looks more like a heartbeat. What or where does the OS sensor go or where does it terminate? In the motronic box? If there are any O2 Gurus out there I need some help.
It ran poorly with the O2 sensor removed and when I questioned RhineWest they said they map their chips in a connected state so we hooked it back up and it still gets pathetic 27 MPG and started surging which it did not do before.

I need a primer on O2 workings. jm

Chris Canning · 03-22-2013, 09:46 AM

Buy and fit a PC,you'll get a new Bosch lamba sensor as well.

JonyRR · 03-22-2013, 11:18 AM

*sigh*
1) the stock narrowband/digital 02 sensor plugs into the motronic cpu under the tank, same place the chip swap went.
The chip swap can be tricky, bent pins and static discharge damage can and does happen.
2) the 02 sensor, either wide or narrowband, is a wear item and recommended to be replaced every 50K miles. If it ever got fed leaded fuel or oil (as in blendzall gold,hahaha) the sensor COULD be poisoned.
chips are a bandaid, and very specific as to exact hardware state, IE you need the correct pipe, filter, etc, for the chip to be accurate. It's the luck of the draw as to how close the chip is to your particular setup. With a chip you are trying to fool a very sophisticated (for it's time and place) cpu that is programmed to look for stoich (14:1 AF ratio) under most less-than-full-throttle conditions. IF your tuner is used to working only on jap bikes I'd like to be in the corner watching, taking bong hits, while he bangs his head into the wall in frustration as everything he is used to doing gets lousy results.
I said it once before, run the stock chip. pull the CCP. do a careful tbs synch, make sure the BBS's are set rite, AND DO a 0=0 butterfly synch and set the TPS to a 380 MV initial set, this richens up the bottom end so it doesn't do a stall off idle.
After all the frustration, cursing and weeping stops, you will STILL go to a PCIII or another intercept box that can map AF ratios OTHER than stoich at part throttle/rpm conditions
if your tuner does not understand what stoich is or instantly know what AF ratio it is....get another tuner

JonyRR · 03-22-2013, 11:22 AM

and a gross richener, like a techlusion that only adds fuel in 3 ranges is also a crude field dressing, not a surgical repair in the hospital.

What you really (and everyone else) wants is a complete replacement cpu that is completely programmable everywhere, but 'teh EPA don' like those verry much...

wswartzwel · 03-22-2013, 11:23 AM

You feeling better Jony?

jmmccauley · jmmccauley's Garage

Would you suggest I swap my chipped ECU for a stok unit and go from there? My mechanic is a BMW master mechanic with 20 yeras... I'll stay with him. :-)

You guys are great and I appreciate your tolerance what for you must be incessant crying from newbies like myself

Chris Canning · 03-22-2013, 12:01 PM

Quote:

Originally Posted by jmmccauley

Would you suggest I swap my chipped ECU for a stok unit and go from there? My mechanic is a BMW master mechanic with 20 yeras... I'll stay with him. :-)

You guys are great and I appreciate your tolerance what for you must be incessant crying from newbies like myself

If you do a search and that'll mean you'll be back in 3 months you'll find the whole board vanished up it's own rectum with chips and god only knows what else trying to find a fuelling solution,the Power Commander appeared and apart from the starting problem with the outside power source,post's on fuelling all but ceased period and that's got to be 5/6 years ago,so you'll have to understand your post is like trying to revive a corpse that's been gone a while

Martin Glasser · 03-22-2013, 07:04 PM

I'll be praying for y'all.

JonyRR · 03-23-2013, 09:15 AM

1) Off Topic: To Bill Swartzy...I just now read your private post. Thank you for the prayers, every little bit helps. I am feeling somewhat better. Still have my degenerative muscle condition, but I had 12" of intestine removed in Oct. and they found a diverticule they missed, that was necrotic and leaking, so I had low grade peritonitis going for who knows how long. I no longer feel like I will actually die every day. I'm officially disabled and no longer able to commute to a desk job, so I'm running a couple of real estate websites. I will post you privately.

2) On Topic: No insult to your mechanic. There are mechanics, technicians and tuners. I'm sure he is all 3, but being bmw-oriented, he might be stuck in one mindset.
It's almost impossible to fool a 2.4 system with just a chip. The rest of the black-box components will be trying very successfully to get stoich while running at less than 3/4 throttle and stoich is too lean to run correctly, that AF ratio is required for cat converter operation only and the germans try very hard to ensure you don't get around it.
IMHO; Get a PCIII or other intercept box or chase your tail forever.