My question is what comes online in closed loop? My car developes a miss or floods the engine the second when it goes into closed. I hooked it to a scanner and no codes or mill light but drove around with it hooked up and it drive fine untill closed loop hits. So I unpluged the oxygen sensors so the car stays in open loop and everything is fine. Is the oxygen sensors the only sensor that comes into play in closed loop?

Any ideas?

 

Yes. The O2 sensor is what comes into play. That IS the device that closes the loop.

 

I suspect that you have an exhaust leak or a bad O2 sensor. BLM learning is enabled once closed loop is entered and the O2 sensor is exclusively responsible for this. If fresh O2 is entering the exhaust stream ahead of the O2 sensor it wiill detect this as an overly lean condition and dump in more fuel to compensate although this usually does'nt cause the engine to stumble or stall but it certainly could. I believe it is more than likely a bad sensor. JMHO. HTH