Often times this surging can be related to a low coolant level and then air in the system which can confuse a sensor. Top off the system and bleed the air from the cooling system. It can also originate from a vacuum leak.
For less than the price of the reading you can buy an OBDII scanner. They run as low as $25 to $30. I also understand that AutoZone will read for free. I don't have an AutoZone in our community and not everyone does.
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Tuesday, December 16th, 2008 AT 4:05 PM