Misfire.. could it be my iridium NGK?

[oakley]

K well I just had the car serviced and I had the dealer fit NGK Iridiums instead of the basic NGK's they use as everyone I speak to keeps going on about the Iridiums being awesome...
Well it drives nice its just on start up when the engines cold it stuggles abit for the first few seconds..It always starts straight away but the revs are too low and the engine rocks...as soon as I rev it, it settles down and all is OK.. any ideas?? Should I go back to the standard plugs if this is likely to be the problem?? Or any other causes I could check first?? Its only done it since the service and engine warm its fine on the start..

[Philly]

were they gapped properly? that would be the first thing id make sure of.

I used the same plugs in my m44 with no issues for almost a year.

[ATF]

IIRC NGK gaps them correctly to begin with, so they shouldn't need to be gapped.

[oakley]

Yeah I thought that but therespose to be gapped from the factory..Im not good with these things and wouldnt have a clue so I guess its back to the dealer for them to confirm! At my cost no doubt