Volkswagen Repair: Rough Idle on 1999 VW POLO 1.6, volkswagen polo, clutch pedal

Question
Hi,
I've just bought a 1999 Volkswagen Polo saloon, 1.6Litre GL. It's a manual transmission petrol.
Problem.
The idle revs are up and down, really rough from between around 800 down to 400 revs. When pulling up at junctions with the clutch pedal down the revs drop right off to 400 or below, sometimes stalling the car. The car is also quite loud and feeds back through the exhaust with a series of little pops after accelerating off in first and second gear.
Any ideas please.
Would be much appreciated.

Answer
Hi Rob;
My expectations are that you have an ignition coil misfire.  Does the check engine light ever come on?  Even if not, I would certainly start with the ignition, especially the coil-on-plug....coils.  They have had a history of failure.  If it's not limited to the coils, it could also include the wiring harness that goes to them.  Good luck.