So I had an issue before with the car hesitating while accelerating, I replaced the plugs and wires and everything was fine for a while. Now the car hesitates only when in lower RPM's usually between 40 and 80 MPH (1800-2800RPM). I'm not sure what it could be but I have a few ideas. First the Mass Airflow sensor is used from a junkyard according to the previous owner, so it's quite possible that is the culprit. Second is the MAP sensor, I noticed that the clip holding the sensor is broken and the sensor itself is cracked. Along with that I saw some oil pooled on the back of the lower intake manifold. It seemed to be leaking from the intake manifold or valve cover. Do you think this would cause a bad enough vaccum leak to make the car hesitate? Third, a check engine light came on for the (vapor canister). I don't think this would cause a problem but I'm planning on replacing it anyway. Anyone know a way to test the MAP and Mass airflow sensors?
