Not sure if this is a strange one or I'm just tired and missing something obvious!

Came to us last week with Engine light on. Read codes with VAG com.

16684 Random /Multiple misfire detected.
P0300-35-10

16685 Cylinder 1 misfire detected.
P0301-35-10

16785 EGR syst insufficient flow
P0401-35-10.

Quick smoke check showed a bad air leak on the EGR to inlet manifold pipe, Repaired, re tested, road test all seems
good so returned car to customer.

A few days later (Possibly the first time the car was used since repair) the customer was back with light on. No
EGR codes this time but the 2 misfire codes are both back. No sign of a misfire on the road but stop start/town
driving or left to idle and the codes return , there is a slight intermittent misfire when idling.

First I did a few basic checks,
Plugs were not great so replaced, Coil (has power stage piggy backed) showed quite a few cracks in the insulation
and although there was no obvious sign of tracking I replaced it. Leads are genuine and look like new, throttle
body was in a poor state with EGR contamination so I cleaned that, Re checked for air leaks. Checked Vacuum when
running, 17-18"hg with a dead steady needle (Although there was no noticeable misfire since the gauge has been
attached). Checked O2 (5 wire), Not great switching at idle but ive never yet seen one of these great at idle.

Scoped Crank and CAM, All looks good.
The inj looks sensible but is the duration a bit long? (Probably should check fuel pressure). There was a small
"blip" on the current just after the inj closing which I guess is just a bit of interference.


Any ideas on the above? Inj duration? and more so where I should head next? Running out of ideas myself!

Cheers.
Steve.