Extreme loss of power?
#13
#14
#15
For these trucks, they prefer copper. I've read that a lot of people in this forum have had issues with platinum plugs.
#16
Thanks for the reply. I've got a high mileage engine - nearly 240K miles, but the top end was redone around 120K miles due to a dropped valve seat. I was thinking that it was worn out, but compression seems ok for it's age - all cylinders close to 120 psi (after cranking 10 or 12 revolutions). The engine runs smooth otherwise. No misfires, no check engine light. Just extremely low on power. With a manual tranny, I have to shift down when going up a slight grade on the freeway, or against a stiff wind. Ordering some RC12MCC4 Champions now...hopefully they'll make a difference. I haven't checked the fuel pressure or pre/post cat pressures yet.