hesitation,bogging when driving and now idiling. tachohmeter jumps up and down on 2000 Mercury Villager

first it started hesitating at 40mph now it does it at all speeds, when idiling. Would think if it was the fuel pump it would have quit by now. been doing it for the past 2,000 or so miles. could it be the o2 sensor? it has 152000 miles on it. would appreciate any help. thanks.

by in Honesdale, PA on August 11, 2012
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1 answer
ANSWER by , August 12, 2012
first you will have to get the car hooked up to a scanner to check for trouble codes then you can hook up a fuel pressure gauge to check the fuel pressure