Hi after some advise .....i'll try and do this as concisely as I can ,,,,,, recently bought a Mondeo 1.8l 2007 petrol and have noticed since basically day 1 that on starting it up the revs stick at around 3500 for a good few seconds before dropping to 1k they then fluctuate between 1k and 2k, until it gets warm then it settles a little bit. Done all the usual stuff ..... checked for vacuum leaks, done a scan (0135 code o2 sensor heating circuit Bank 1 position 1) checked that out replaced it .....still the same. so took throttle body off and Idle Air Control Valve and thoroughly cleaned them both still the same, so tested the idle air control valve resistance that was fine ..... now the weird bit ............ i forgot to replace the plug on the air control valve, started the car and it was fine ........ when I realised i'd forgot I replaced the plug and the car did what it was previously doing ....... so I thought I'd cracked it, bought a new valve fitted it today and .... no change .... i'm now at my wits end ......... can anyone help