Absolutely positively give it a seafoam treatment. I did it Saturday on my P5 with my usual skepticism of miracle cures, and am now a believer. I had a problem since I got it where if the rpm's suddenly dropped the engine would stall, or it would stall when waiting at a red light, all when the engine was warm. I was mentally bracing myself to pull the freaking EGR valve off to clean it but decided to put some seafoam in it instead.
After putting about 1/3 in the intake via the pcv hose (use a funnel) and the rest in the crankcase she now idles like a champ. Be sure to let it sit for awhile before trying to start it again, the instructions say do it while the engine is running, but mine wouldn't idle while pouring and I didn't have a helper to keep the rpm's up. Let it sit for about 10min (otherwise it'll just crank and you'll have heart failure that you broke something) before starting. Do this outside with the car door closed and windows up, because that white smoke they say is normal is actually like a fricking smoke screen that goes on and on and on. Let it run with the engine rpm's around 2k for 5 min or so then take it for a 15-20min aggressive run and laugh as everyone stares at you for the incredible plumes of white smoke coming out of the exhaust. Keep driving until you can't see the white smoke anymore.
See if that helps.
