My wifes 2002 model 1.4 Astra has developed a miss-fire while it,s at cruising speed it does,nt happen very often, checked one plug only and it seems to be the correct colour ie light brown.
Checked to see when plugs were last changed it was 06 and it,s only done around 7,000 miles since.
Would it be advisable to change them ? they are Bosch plugs, is there a gap setting on them as I can,t see how with there being 2 prongs on them.
Or is it something more sinister?
Any help would be most appreciated