do i have to stick with iridium plugs if they were mapped with them in??

[richard cash]

I had my car mapped at reworx and they put iridium 10\'s and 11\'s in them. I think i now need to change the plugs after 5K miles as the car seems to hesitate on any boost or highish revs (+3.5K). Now the thing is the plugs they sell are £100+ P&P. Do i have to stick with these or can i use copper 10\'s and 11\'s.

ive emailed reworx this question also but they wont be able to get back to me until at least monday id have thought.

[Laeeq]

Have you been doing any stop/start or driving in traffic and short journeys?  If yse then they may have carbon build up.  Its worth taking them out giving them a good clean; best is to burn them on a as cooker and then clean with wire brush...After installing them back, take the car out for good drive on boost but please be carefull if the roads are wet.

They should last more then just few thousand miles as i had a similar iridium cold plugs in mine and as the car was mapped with them, i had to replace them with same or similar iridium plugs.  I now use HKS iridium plugs from RHD japan and its about 70 quid for 4 delivered and can be foun in all heat range and are made by NGK for HKS.

[richard cash]

recently ive been doing loads of stop start 5minute journeys with no boost. Ive not had any flooding issues but this problem started when i took my car for MOT and they was moving it all around the shop floor to accomodate other cars (probably must have moved it about 10-12times for 1minute at a time.