Bonneville America Forums Forums Technical Forums Exhaust Fuel injection & O2 sensors??

The O2 sensors are in the headers - not the mufflers. The 02 sensors only function at 0% throttle when they monitor the exhaust mix for unburnt fuel and tell the ECM to send more air via the AI so the unburnt fuel can burn in the headers. This is what causes the popping on decelleration - it also contributes to the snatchy throttle syndrome at 0% to 5% throttle as the ECM makes dramatic richness changes once the throttle is re-applied.

Sooooo ... the 02 sensors can be disabled (turned off with Tuneboy) and the AI removed without harm to the engine and without affecting performance. Their only function is related to emissions at low and zero throttle.

The only complication may be if the EFI bike in question has catalytic converters in the headers and that's a little out of my depth (but some have raised concerns about the catalytic converters melting without the AI operating). The BAs and SMs in Australia don't have catalytic converters in the headers (they have them in the stock mufflers).