Think it is time to change the plugs, not really sure what is in it, but think they where iridiums, but has been running a bit rich on boost so I get the feeling the plugs are getting to there used by date.. The car runs bout 17/18psi with a vf22 on 220k engine. What plugs would best suit my car, I was thinking quite a cold plug due to the boost factor even though they are a bit hard to start, car also has antilag..