[dna]

After 200kms I thought it would be a good idea to change the plugs and wires for the 1st time. Bought the iridium (41-110) and OEM wires. With doing only limited googling, I thought these were supposed to be gapped at .06mm so I did that (they were 0.04mm out of the box).

After installed these new plugs, the idle was smooth and revved nice. Took it for a drive and the truck could barely get over 100 km/hr. After a few minutes I got P0151 (maf sensor) and p0300 (random misfires).

So I pulled all plugs out again and regapped back to 0.04. Installed them, but same thing. Could barely get over 100km/h and same 2 obdii codes.

Could I have damaged the plugs when I first gapped them? My method was sticking a flathead driver into the gap and lifting up - could this have damaged the iridium tip?? Is there anyway I can tell if the plugs are bad other than buying a whole new set?? BTW - I dropped one of them about 3' onto a concrete floor - when it first happened I looked at it and it looked fine. Could that have damaged that one, and is it possible if I have only 1 bad plug that I'd get these symptoms and codes?? I would have thought if only one plug was bad that the p0300 would have given me a number in the last digit to tell me which cyclinder is misfiring - doesn't p0300 mean all (or more than 1) cylinders are misfiring??

Thanks