Intermittent misfire and poor idle.

The vehicle had been serviced and a misfire problem was checked.

The spark plugs were replaced to rectify the misfire.

After one day, the same problem returned so the vehicle was taken back to the repairer.

They had the vehicle for a week but could not find the problem and in frustration, put it down to an engine management issue.

The owner advised that a new coil set was tried with same result.