I am running the ngk bkr7e plugs because I should be running a resistor plug with the S300 to avoid any interference. The S300 will stop datalogging randomly anyways. I now need a couple set of colder plugs (8's) to retune my car but I dont want to run into this problem again. I had a set of the NGk iridiums before the current ones for only a few days and I dont remember having any datalogging problems. I removed them and went with the copper ones because I heard the iridium tip will do major damage to the engine if it ever breaks off. What do you guys suggest I do? Should I be looking at something other than the plugs for the issue?

 

Datalogging problems can be caused by any interference in the ignition system.

-Cap
-Rotor
-Plug Wires
-Coil

Anything not oem can be a source of problems.

A good resistor type copper plug should work fine.

 

Could it be that they might be wearing out? I should replace those anyways. I have my msd box under the dash on the passenger side near the computer BUT this problem is only recent. I've had the S300 for almost a year now.