Torque fault codes and smokey engine bay Boxer help

[gordie303]

I got me a cheap OBDII Scanner for my boxer 2.2 VIN VF3**************[VIN obfuscated, can be read by forum staff] and it's throwing out codes
P0094 Powertrain
P0101 Powertrain Mass or Volume Air flow circuit
P0603 Powertrain Internal Control module Keep Alive Memory (KAM) error
P0600 Powertrain serial communication link ( pending Fault)

I've just replaced 3 glow plugs (4th would not come out its hole)
There is smoke coming from under the bonnet Drivers side by the looks but can't actually see where its coming from (not exhaust)

I've had a quick google but can't see anything relevant to my van

[gordie303]

Still having issues with the codes, and not reving past 3000 when driving

[doctle]

Generic code readers don't work great on French vehicles.

[gordie303]

Had new egr fitted all codes cleared and none showing now but still wont rev past 3000 when driving and not much power uphill.
put in new fuel filter last week, what would be next thing to look at?