Ford Repair: 2000 Ford Taurus, vacuum leaks, ford taurus

Question
Hi Jason, I own a small used car lot and repair shop and need your advice on my 2000 Ford Taurus with the 3.0 flex-fuel engine. Between 1,500 and 2,000 rpm the car bucks and stutters, it doesn't matter if the engine is hot or cold, sometimes it barely does it and other times it does it badly. I scanned for codes with my cheapo scanner and got nothing. I went ahead and replaced the plugs, wires, fuel filter and cleaned the MAF with no change. I understand that the egr pressure sensor or DPFE is a common problem in these vehicles, I unplugged the sensor and went for a drive and it still does the exact same thing. It seems odd that unplugging the sensor didn't trigger a check engine light but I guess that I didn't drive it far enough. Would you recommend that I try replacing the sensor before I shell out $$$ at a Ford dealer or do you have any other suggestions? Thanks alot for your help!

Answer
Hi there, sorry for the long wait.  Yes the DPFE is a problem area but you could probably get that replaced at a dealer for free under a recall if you tell them it set a code and you cleared it. That shouldn't show up on a cold engine anyway.  I have seen camshaft synchronizers fail on those (the shaft and sensor that replaces the distributor) but usually will set a code. I would triple-check for vacuum leaks and give it a good drive and see if you can make it set any type of code.  A fresh tank of real gasoline won't hurt either.  Hope this helps you out.
Jason