Have not got the book in front of me, but you can run disconnected. In the thottle body there is a fine wire that is fed juice when engine runs, the wire heats, this represents a resistance value, the ECM sees this and converts to an equivalent amount of air flow (sets air/fuel mix ratio), open throttle = equals more air = cooler wire = changed resistance value = ECM adds or subtracts fuel = best possible fuel/air mix etc etc - even though you have an air cleaner, dirt etc will get thru the throttle body, and just loves to stick and burn onto the wire, therefore at the end of your drive when you turn the engine off, the controll relay will activate for "x" seconds, switching on the "MAF burnoff relay" which applies a full 12v to v wire, heating it to a trillion or so degrees, which vapourises any sh#t stuck to the wire. Next startup means you have a clean wire and perfect air/fuel mix. There are three relays, inter-related, they are a P in v A. I'll find my books and see if i can give u some more clues but, it is easy to confuse between the relays. Disconnection should be ok for the short term, but obviously as the wire gets crappier, then fuel economy and perormance will be affected. VP
