O2 sensor engine code
Need some advice here. Been dealing with the Ďcheck engineí light on since I installed a Graves exhaust with a Power Commander and Autotune. As has been noted on the forum before, the PC and Autotune are NOT shipped with an O2 optimizer plug anymore, so I left the old O2 sensor connector open. As I would expect, this sets off the Ďcheck engineí light, and itís been on awhile.
Had the bike dyno tuned and all went well. The guy who did it commented that the engine light would go off only if I had an optimizer in the circuit, and recommended I get one on eBay. Found one for the bike from Europe and finally got and installed it. Ran fine, but the light never cleared after numerous rides. I brought the bike in for a state inspection and had the code read - 67 (P0030) OX SENSOR MALFUNCTION OPEN OR SHORT. But after reading and CLEARING the code, the light immediately tripped again, with the optimizer in place. Of course the dealer wonít help - itís not even close to stock.
So Iím wondering if the optimizer has the wrong resistors for this bike. Unfortunately, the tech says the code is OPEN or SHORT - you canít tell which is the case.
With an ohm meter and by reading the resistor codes, they are 330 ohms for the heater, and 47K ohms for the sensor. I have no reference for the sensor resistance, but the heater value may be off. The service manual says the stock O2 sensor should have a resistance value of between 13.0 and 18.5 ohms. If the ECU is seeing 330 ohms, all I can think of is that since this is way too high, it may interpret this value as an ďopenĒ and continually trip the light. I could try an 18 ohm resistor here, but for a 12 volt supply that is 8 watts of power dissipation - not trivial and requires a 10 watt rated power resistor. And that would be expected as itís a HEATER element in the sensor. But from photos Iíve seen of old optimizers, the resistor is nowhere near the size of a power resistor of this wattage.
So to get to the point - does anyone have experience in this area? And if you have an optimizer that works with a PC and Autotune, can you check the resistance with a meter and let me know the value?
I would appreciate any help in solving this as itís not just annoying. It would be nice if the light was ever tripped for another reason I would know it...