bought iridium spark plugs but need help

[bryanhoule]

Regarding the low idle, I experienced it as well, and it was also temporary. I just replaced my original spark plugs (they were Denso) with new NGR IFR5T11, at 82,000 miles. Original plugs looked pretty good as far as I could tell (not an expert). They all looked the same, which I'm sure is a good thing (don't need to be an expert to know that).

Anyways, after driving around the block a few times for the first time since installing the new plugs, i parked at home and let it idle. RPM was around 450 to 500 RPM, and causing a semi shaking/ vibration of the car, that i could physically feel. i rev'd the engine for a minute or so and it went away and hasn't come back.

My theory is that the CPU is somehow re-calibrating to the new plugs, but that's only a guess.

By the way, replacing your own spark plugs is easy! I didn't use a torque wrench (too expensive), but was cautious to not overtighten, just snug. i used a "single hand" method to be sure i wasn't overtightening. Also, I put a very small amount of anti-seize on the threads.