Originally Posted by
GraphiteGhost

? What makes you say this? The car is having a hesitation issue. Getting that fixed should be first. The closest thing to your suggestion might be a throttle pedal acting up. So, help me understand why the spring booster advice? Unless, the spring booster is less expensive than a throttle pedal, and it might make it better? That seems to me a patch until the pedal fails completely (if that pedal is his issue).

OP, was the car running much better before you noticed the 'hesitation', or did it slowly creep up? How many miles on the car? You said you had oil leak into your plug, what plug (spark or electrical)?.
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The cam position plug. The electric connection side of the sensor had oil in it. My car has 91,000 on it now.