2001 Trooper Spark Plugs

Use the same Denso K16PR-P11 plugs that were originally installed. Run an Internet search - you can find 'em for $8 - $10 each. These Troops are extremely sensitive to resistance variances from OEM plugs, and you risk the dreaded CEL if you use anything else. AND, be very careful taking the old ones out. At 100K, the threads have probably seized in that aluminum head (assuming the plugs haven't been changed previously).

I've been running Bosch 4-electrode version (forgot the name) for some 10K miles with no problems now.

Peter

I'm relying solely on the experience of many others who own '99 and later Troopers. Prior to '99, it seems Troopers weren't quite so picky about plugs. Just curious, what year is yours?

You could be right, I have 98 Trooper.