I had a mechanic replace my exhaust headers a while ago on a 2.2 L 4-Cyl. Engine and he had to remove the A/C unit to get to it. Now when I tried to use my A/C system it is not cooling down as it did before and when I tried to add more oil/frion mix into the system, the gauge was telling me that there is well over 100 psi of pressure inside and that I obviously shouldn't add any more. During the process I had the system on Max A/C and the fan on high. In the middle vent there were small bits of sponge being blown through it. Through my random search of answers I think it might be the sensor that controls the compressor and tells it when to turn on/off. Any suggestions or ideas would help....