99 Mustang GT 4.6 Litre 180,000 w/ no mods Issues: Low Idle, Reduced performance, stalling, missing, ticking, ac issued etc... Repairs: New Air Filter, new IAC Valve(reset ECU for idle learning), new EGR Valve, cleaned MAF Sensor, new Spark Plugs, new Alternator, new Serpentine Belt, new Fuel filter, and checked for vacuum leaks with Carb Cleaner, no leaks found. - I also poured Seafoam into my gas tank - ticking started. I am at a loss. The vehicle is running better but still idles low. It drops down to 500 - 600 and then back to 700. When I turn on the AC or Defrost, it nearly dies after depressing the gas pedal. Any other help or ideas?