Ivica - On the top of the Air Pump is a vacuum operated Valve called the Divertor Valve. It is intended to allow the pumped air to flow to the ports at the rear surface of the engine heads to add oxygen to the exhaust flow while the engine is cold. When the water temp rises, the Computer signals the Vacuum operated solenoid to do several things; one is to divert the oxygen flow from the Divertor Valve into the exhaust system rather than from the engine heads - this flows to the rear cataylic convertor to add oxygen to the exhaust at that point. The valve in the line from the pump to the exhaust system is a check vvalve or also called a one-way valve; the air can only flow one way. If it does not, and yours does not, the hot exhaust gasses go backwards and destroy the valve. It must be replaced, but your exhaust system also needs attention. It would seem that your cat convertor is plugged to some degree that allows the gas to flow backwards. Some other items the happen when the engine warms-up is the vaccuum cannister, behind the right front headlight, which stores gasoline vapors, is allowed to purge, also by another vacuum line from the solenoid, this is done at this time rather than earlier so as not to disturb the mixture ratio of gas and air during warm-up. Your problems are somewhat confusing in that both of the two valves on you car have melted. The vaccuum solenoid on the bulkhead on the passenger side may not be functioning properly. The air pressure from the pump must be sufficient to overcome any backpressure from either the engine ports or the exhaust sys connection on the cat convertor. Since this is not happening, I'd check the pump output first. This pump, as far as I know, is not reparable, almost any GM pump for a V-8 engine ought to fit - save all of your Chrysler mounting pieces. If you live in an area where the exhaust sytem output is not "inspected" or required, I'd remove all of this equipment since the car will run quite well without it. You can obtain the two head port blocking covers from the Canadian cars or Chrysler itself. If you need a part number, let me know. Then all that you'll need is a threaded plug to screw into the side of the cat convertor. Hope this helps. Bob Harris - '81 EFI