backfiring/spitting due to new extractors?

[JSTCOZ]

Hey guys, had extractors on for around 3-4weeks and all of a sudden the car is spitting and backfiring under pressure. I can't spot the issue. but heard that after a few weeks it's a good idea to get your extractors tightened again cos they have begun to adjust to your system? that sound right? Also maybe the guys i went to just didn't tighten them enough?

[Snap-on]

Go back and see Aaron. He will sort you out

[JSTCOZ]

Go back and see Aaron. He will sort you out

Has this happened to you? Also do they do it for free or not? just getting my VX converstion and driving up to hervey bay for the weekend coming, shame they dont work weekends! Reckon driving with it will damage the car>?

[clown]

when i got mine done had the same thing some how the leads were damaged so just look at the number 1 lead i changed mine and away it went
but now changed my plugs yesterday and miss fireing again so now need to see whats done that and i dont think its the ngk plugs i hope not anyway they cost 170.00 so go to holden 2moro and see what a new set of leads are going to cost me

[tripletsdad]

my bet would be if u changed the plugs yesterday and it wasnt missing b4 u changed the plugs then they may be faulty take them out and check them for cracks on the porclain also check where the gap is if that piece which sticks out moves plug is faulty