My girlfriends '97 t-bird has been acting up lately and it hasn't been correctly diagnosed by two different mechanics. The problem started about a month ago, when using the air conditioning, the car would hiccup or hesitate at about 2k rpm, drop to about 500-1k rpm as if it were about to stall and then recover once a little more pedal was put into the acceleration. In the past couple of weeks, the problem has started happening all the time, with or without the air on, and seems to be worse later in the day than in the cool air of morning.

She's had the spark plugs and wires replaced to no avail, I've got a scan tool and checked to see if there might be a vacuum leak but that reads fine. There are no trouble codes coming up on the scan tool at all.

I've come across an article that I cannot seem to relocate where one individual solved a very similar problem by replacing his Camshaft Position Sensor on a 96 t-bird and was hoping to get more input to determine how to verify that this might be the cause of her problem or any other words of wisdom regarding these symptoms.

thanks in advance!