Misfiring

[L3WLM]

My 172 seems to be misfiring, i have replaced the spark plugs

what sould i replace next HT leads? Coil packs?

Cheers,
Andrew

 

[Scex]

Mines in the garage at the moment and had an annoying dgjsbdjkgb sound coming from the back due to misfiring, i changed my sparks without noticable change but then changed all 4 coil packs and fine now, runs better than before.
Want to watch out though if its been like that a while your cat could be wrecked like mine was. Sports cat down

 

[davebem]

Does it just missfire when idling?? Its normal for them to splutter a bit.

 

[skiptontweed]

Mine did this - have a good look at the coil pack -sometimes they overheat and split. New one cost me £50 from renault.

 

[L3WLM]

Just had the RAC out and its not misfiring too bad, they dont think it will be the coil packs

What else could it be ?