Hi all, I'm having a problem with my Mondeo ST200 V6. It idles a little lumpy, picks up fine until about 4300rpm, hits a flat spot, then flies off again at about 5000rpm until the redline....

It's been regularly serviced at least every 10k, I have checked the IMRC unit, which is working fine and I have recently replaced the MAF sensor ( a garage diognostic check revealed a fault code related to this) but nothing seems to have changed... still wont rev smoothly throughout the range!

It's really annoying too because if I sort this out, the car will then be A1 (which is rare for me! lol)
Someone on the ST owners site suggested the knock sensor... does this make sense to anyone and where might i find it?

Any help would REALLY be appreciated.

Lee.