Cadillac Repair: 95 STS Stalling, fuel pressure regulator, throttle plate

Question
Sorry I forgot the engine size! It's the 4.6 Y-VIN Northstar and please know that I have had nothing but Cadillac's since I was 16 starting with an 84 triple white Eldo Biarritz. This STS is black on black with every single option offered in 95. It is flawless in and out with every service done as prescribed since day one. Nothing but Mobil-1 synthetic done at 25% oil life every time. Cooling system  maintained with Dex-cool and pellets, never runs over 219 degrees even on a 90 degree day idling in traffic plus it does not leak a drop of anything or burn oil. I have a Stainless-steel cat-back Corsa exhaust and platinum  Bosch VR-4 plugs. The only things it ever needed was the Fuel Pressure Regulator & MAP Sensor outside of it's regular scheduled maintenence (A,B,C & D) and continues to show no code other than P095 Stall detected. Your help is greatly appreciated!  

Answer
This is mostly caused by a blackish residue builup around the throttle plate area. Clean both side of the throttle plate area and the throttle plate bore of all this residue. You will also find a small hole in the throttle bore just below the throttle plate that is for your idle speed by-pass. spray some aerosol cleaner such as carb cleaner or similar into this hole as well as to clean the throttle plate and throttle bore areas. Also check your egr ports (remove EGR valve for carbon buildup on the bottom of the EGR valve and in the EGR passages.