My 2002 2.3 Ranger recently developed a severe case of pinging. I searched YouTube for solutions and tried most things suggested (Seafoam, MAF sensor, etc.) but nothing worked. Somewhere I had read that the Intake Manifold Runner Control valve should be checked - but I didn't know how to check it. I disconnected the hose from the intake manifold and plugged it. That caused the Check Engine light to come on - but the pinging was gone!! I knew I was on to something and found a replacement IMRC at Discount Auto Parts Online -- PartsGeek.com - Domestic & Import Auto Parts Warehouse
for less than $100. It arrived in 2 days and I installed it. I disconnected the battery cable briefly to reset the computer and drove the truck. No pinging, no Check Engine and it runs great!