Laguna II petrol engine vibrating when idle

Hello,

I hope I can get a hint on this one.

Engine vibrating when idle ,revs not stable especially when air-con is on.Fuel consumption high with low speed ,at 60 mph on motorway -fuel consumption fine.

When down hill and gearbox in idle at 30 mph trip computer calculates 3l/100 km consumption-should be around 1l/100 km

No errors in the ECU.

Seems to get worse after engine warms up.

So far:

-new coils and spark plugs.

-Throttle body removed and cleaned.

-ECU connectors removed and cleaned with contact spray.

From the forum entries I see that the throttle body replacement is not a solution-I was given this option next.

Could it be something in the injector?

I did use a can of injector cleaner.

Thanks in advance.

Regards