Camshaft Sensor is inside the engine near camshaft. I had it replaced a year ago. your looking at 300.00 + for job. Ask to have complete dino first to make sure of problem. The sensor itself mounts on the outside of the timing chain cover, just left of the hamonic balancer. Easy way to get at it is to remove the right wheel and the splash guards. I understand that it is usually not the sensor that fails, but the magnet that is attached to the cam gear under the cover. As the gear spins it triggers the sensor. The magnet is an $8 part, but you have to remove the timing cover to replace it. That's a $300 to $400 job. But first make sure the magnet's bad. You can use a mirror and flashlight to see it. If it looks ok, and still has good magnetic pull when you touch metal to it, it's probably OK. Autozone can test the sensor and see if it's working. It may simply be the wiring. Once you find the sensor, unplug the wires from it, inspect, and reconnect, then see if you get the same problem.
The 1991 Buick IAT sensor can be found in the air intake hose. The IAT sensor will be between the air box and the top of the engine.
On vehicles equipped with a camshaft position sensor, it is used to help the PCM determine the correct firing order.
It's just behind the harmonic balancer.
check crank sensor
The Buick Park Avenue Started In 1991
show a diagram of a buick park avenue crankshaft sensor
IS CALL CAMSHAFT SENSOR AND IS LOCATED ON THE RIGTH SIDE OF THE ENGINE , ABOVE THE CRANK PULLEY You will have a crank sensor, but it won't have a cam sensor. it dose have a cam sensor, on the timing cover left sind of water pump
check the MAF - Mass Air Flow Sensor