I've recently replaced a nackered plug with a non-gapped plug and a week or two ago i noticed that the car has started to missfire badly when hitting boost when cold (10-15 mins of driving) but its fine when it has warmed up. Would the non-gapped plug course this? I know the gap should be .7 but what are Champion plugs gapped to from the factory? Just seems stange that its perfectly fine when warm

Cossie management / greens / 3bar etc.
Cheers,
Dan

 

did you just replace one plug? Im positive there is nothing wrong with doing that, but as they are soo cheap anyway, Id replace all 4 at the same time.. and GAP them all at .7

 

Cheap??? I've gone through £75 worth in 250 miles