hello,
right to add to my pretty poor post (very tierd and annoyed when wrote that).

Took for a test drive drives fine very responsive no mil light untill about 10 mins in to the drive and i pull over and then the mil light comes on, re scanned and the following fault codes are on again.

P0300 random multiple misfire.
P0304 Misfire cylinder 4
P0134 O2 sensor Bank 1 no activity
P1125 fuel trim system too lean.

Now for my tests.

tested maf with a multimeter.

1.4v idle and 3.9v sharp rev.

Checked for all air leaks all ok.

done a block test all ok fluid didnt change.

compression test 12bar all good.

front o2 sensor not changing form 0.050v very low
(the 3rd brand new genuine sensor fitted)

there does seem to be a very slight misfire on idle but runs lovly.

im at a bit of a loss with this one.

hope theres some one who can help.

regards mike!