2003 1.8t Lost Power Suddenly

Firstly
Jetta 1.8t 5 spd
Revo'd (chip)
Diverter
Exhaust
Cold Air Intake
85,000Km

Merging onto the hiway this morning, there was a mild pop sound.
Maybe more of a feeling than a sound.
Then a loss of power.The MIL light is on and flashing.
At the traffic light it Idled a bit low but the MIL light went out.
Under acceleration it came back on and the car feels like its running on 3 cylinders.

Nursed it to work and parked.
Went out at break and started it and it is definetly running on 3 cylinders.

Any Ideas as to what to start with?

My wife picked me up a coil pack @ dealer $40.82.
Went out at lunch and replaced # 1.

That did the trick.

id reccomend replacing all 4 now.. there a common failure

I took it in today for the N4 recall. Brake light switch.( Never had a problem but, oh well...)
The Mechanic there said the coils are suceptable to premature wear due to improperly gapped plugs.
He suggested I replace the 4 plugs.

It makes sense really,if the coil has to try harder to send the proper voltage through an improperly gapped plug ( from wear or heat/cold ) I could see that having an effect on the life of the coil. He recommended 60k for spark plug change on the 1.8t.

At 84k it's the least I can do for my baby.