Suzuki Club UK

Hi all, need some help!!

08 Vitara 1.6 has started misfiring when it gets upto temperature both when idling as well as been driven. When left to cool down seems fine until it seems to reach a certain temp again, before fan cuts in, then misfires again and won't stop until its cooled down again!
Searched everywhere for any similar problems online cant find anything. Took it to garage they replaced egr valve, gave it a road test said it seems fine! Obviously not as did it on the way back from the garage!
Any ideas?

Has it got coil packs? If so one of them could be on the way out

Yes it has, how can I check the.?

Sorry mate I have no idea, all I know is we have a Jimny in the family and that has had the problem a couple of times. I suppose you could try the old way and pull each lead in turn when it’s having the problem