I just recently purchased my 850. Normal aspiration, no mods, etc.

I have replaced the MAF sensor, Throttle position sensor, cleaned throttle body, fixed the PCV connections and cleaned flame trap. Still same problem(see below).

I do not have a check engine light. When the TP sensor is plugged in it idles well but when stepping on the throttle the car 'boggs' down and then slowly picks up... if I don't press hard on the peddle. Then at around 3500 RPM it does the same thing. If the A/C is on it is more pronounced. Another twist... when I first start the car and go it does not happen until about 5 minutes, then the issues start. The car can be warm or cold.

With the TP sensor unplugged the idle is around 2000 RPM and the symptoms are not as bad, but still there. (the check engine light does come on, of course). I have looked for vacuum leaks, etc.

I put fuel system cleaner in it, and have just now replaced the plugs Bosch platinum +4. I am also in the process of letting the entire system reset. Unplugged the negative on the battery.

Anything else that I do? Any suggestions or has anyone had the same issues? Thanks in advanced for you help.