matt in tulsa
New member
Just purchased a 1999 4runner v6 4wd sr5 auto 110K mi. check engine light is on and gave a p0171 engine lean code. did search on boards and found maf sensor needed to be cleaned. have not had time to clean it yet, will clean this weekend. While in park, engine will rev up and down from 700 to 800 rpm. The fluctuation is rythmic, up and down at same rate continuously. What could this be caused by? Is this something of major concern? Only problem with vehicle, otherwise very happy with purchase. Any help would be appreciated.
Update: The fluctuation also occurs while driving. You can hear and slightly feel the vehicle surge. It is barely noticeable.
Update: The fluctuation also occurs while driving. You can hear and slightly feel the vehicle surge. It is barely noticeable.
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