Just got a bazzaz Z-Fi with ZAFM for my Euro spec gen 4 with the o2 sensor at the exhaust. Cat removed and reinstall the stock o2 sensor side by side with the bazzaz o2 sensor. Without the stock o2 sensor the Fi light will always be on. With the stock o2 sensor I cannot properly tune the AFR with the bazzaz coz the stock sensor will overide the bazzaz sensor. Tried the resistor mod but in vain. Is anybody out there have the same difficulty and come out with a solution, do share it in this forum. Dyno Jet do make the o2 sensor eliminator but for the ealier models not for gen 4 yet.