i have just changed the zorst on the v6 and filled her back up with petrol, at first she would idle at 600rpm then when she got hot started running at 1500/2000rpm, dont think its lambda, possible ICV??
Sounds daft but have you taken it for a long harsh blast? Iwas getting idle problems and after a ll else failed, thrashed the guts off her, and it went back to normal. Not the technical advice you want but a suggestion.
Idle issues have dogged me since owning the V6. MAF, LAMBA all changed, runs sweet as a nut for weeks and goes wobbly once in a while and then back to normal. Had the ECU remapped just in case. Still the same.