So I have changed the IM with new gaskets and coolant hoses, new exhaust gaskets. Had to bang the exhaust around for a while to get it lined up and the O2 sensor was getting the brunt of the abuse. Upon reassembly I had CEL and code 1222 and rough idle changed out plugs and idle is much better but threw code after engine warmed up assuming the O2 started reading again. When I pulled the plugs one was "dead" with no gap, don't know how that happened but it did, fixed that plug and plug the rest and reinstalled the Russian Bosch plugs and it ran great for 10 minutes and threw CEL #1222 and idle rough again. Put in new NGK plugs and idle was good and then threw code after warming up and idle was not quite as smooth. Could O2 sensor be bad without getting a 1221 code? we sprayed down the IM with WD40 without change in idle and thought a defective temp señor would idle rough until it warmed up and O2 took over. Runs great at fast idle and MPG is unchanged. Knew I was dumping gas in #3 cylinder with dead plug air first but now not sure why I am getting the code. Any ideas? Prior to changing IM, adjusting valves, exhaust manifold I had no problems! Note to self...leave well enough alone! May take it to BMW shop as I am getting tired!