Grand voyager Mk5 in limp mode and now imobilser has locked on
 

Hi Guys - hoping someone maybe able to help - but of a long story but will do my best to keep it breif - we bought a 2008 Mk5 2.8ltd grand voyager at the end of April private sale but the guy was a mechanic and had done all his own work on it - on way home it went into limp mode - took it straight back to him and he plugged it in and diagnosed the MAF sensor he cleared the fault and got it running and said he would order a new one - it drove home fine and we only drove it very short distances occasionally it would revert to limp mode but it would seem to sort itself out after a couple of minutes we waited for the MAF sensor to arrive the seller promised but it didn't come we sourced a second hand one from a breakers and fitted that it then the seller sent what he thought was the correct MAF but it was the cylinder one not the rectangular shaped one we needed.. The vehicle hadn't gone into limp mode since second hand MAF was fitted - until Thursday when it suddenly went into it on the way from Newark to Lincoln on the A46 we turned round and limped it back home to Newark - my husband plugged it in to his diagnostic tool and it threw up code 0966 so we wondered if the second hand MAF had gone bad so ordered a new one overnight for Friday - we fitted it yesterday afternoon and on test it ran really rough and then went into limp mode with the fans running all the time even with ignition on and engine not running we stopped and he plugged it in and threw up codes of 0966 and 0237 we started it up and again it ran really rough like it was hunting, drove around 200ft then it cut out and the imobilser is permanently on (can only take out of park via manual shift lock) and the red light on console is flashing - we have contacted several mobile mechanics to see if anyone can come and look it it but so far no joy on that front... Any help very much appreciated - incidentally last week as we hadnt used it the battery had gone flat and was told it was dead so went and bought a new battery - but the guy supplied us with a standard battery for it not a yellow top spiral battery - but it was fitted and had been using it with the standard battery and just wondering if these problems could be related to that - we have been and got a new spiral battery this morning even though the guy at the parts insisted that the normal battery he supplies was correct but obviously can't test it as it's locked in imboliliser mode... Again apologies for the epic post just thought it best to describe what's happened - we even contacted the guy we bought it from but he says he is away until end of August so can't help us - no surprise there then..