aRacer AF2 Professional Wideband O2 AFR Module is the new and improved wideband AFR module that now comes included with a Bosch LSU 4.9 wideband oxygen sensor! The AF2 is a better upgrade over the older AF1 model! The cable splitters are NO longer needed! This simplifies everything! The AF2 is the latest and greatest AFR module from aRacer. 
 
aRacer AF2 Professional Wideband O2 AFR Module now comes included with a Bosch LSU 4.9 wideband O2 Sensor! aRacer has significantly improved the design and function of the AF2 to give it a much more stable and quicker AFR reading. They have also built the harness so that it would plugin directly to the aRacer ECU without the need to purchase any other splitter or additional cables. By doing so, this has made the installation much easier and simpler, which the need to tuck away unused connectors and lengthy wires from the splitters. 
Professional Air Fuel Ratio Module AF2 
 
High accuracy and high-speed response
It can be realized "Closed Loop Fuel Compensation" with Stage 2 or Higher ECU (RC Mini 5, RC Super 2, RC Super 2 Gold)
No need for calibration, just plug and play
Employed BOSCH LSU 4.9 wideband oxygen sensor
Optimal design for AF2:
Volume reduce 38%
Weight lower 53% 
Improved performance!!!
Simple wire connection
Data results are much more stable and clearer.
Bosch LSU 4.9 wideband oxygen sensor included
Response +37.5%
Minimum operating voltage lowered to  8.5 V
Measurement accuracy up 80%
Heating power consumption reduce 25%
Maximum operation voltage increase 5%
Lifecycle increase 56%
Ｗarm up time faster 50%
 
NOTE: A 18mm o2 sensor bung is required on the exhaust header. If your exhaust header pipe does not have an available o2 bung, then you would need to add one.