was on the motorway got up to 80mph and the light came on for engine and transmission electronic problem (car with a spanner in it) so i turned the car off and on again and it was fine...

but on the motorway again today hit 80mph and light comes on again, and when it comes on the performance of the car decreases dramatically (until i turn it off and on again...)

but yeah its only when i go just over 70 that this happens :S

now i've noticed in recent weeks that my clutch has started to squeak a bit and become slightly stiff i dont no if its got anythin do with that?

but im an economic driver always change gear asap (unless on the motorway which isnt often) so i dont know what to say?

any ideas will be appreciated (apart from dont go over 70 cos the problem is still potentially there!)

forgot to say its a mk4 1.6 sxi 64k miles

just done the paperclip test and got the code 0607 any ideas? according to the mk5 error code list (which is apparantly the same as mk4) i get these 3 answers:

P0607 Knocking sensor circuit malfunction B-022
P0607 Knocking signal module; control device to replace B-022
P0607 controller replace error (see above)

what is that? and is it expensive?