Chrysler Repair: Pacifica runs rough @ 2500 rpms, 4 digit numbers, vacuum problem

Question
My 2005 Pacifica 3.5l has all of a sudden began to stutter as if the fuel is insufficient. It will run fine as long as i don’t reach 2500 rpms and seems to shift through the gears allright. I can get it up to 65-70 mph before the rpms get to that point and the stuttering begins. Also, while in park, i slowly press on the accelerator and once again, at 2500 rpms the stutter starts and it will not go beyond 2500. Could this be a vacuum problem or fuel issue?

Answer
Hi Jay,
It could be vacuum, fuel, spark, but to find out the best thing to do is get a fault code readout of the engine controller which has the capability of self-diagnosis. Try the ignition key:"On-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage changes to give you some other 4-digit numbers which would be the fault codes. Then let me know, and also what engine you have and we'll go from there. If nothing shows up that way then you can get a free readout at an Autozone parts store or a lower cost readout at an independent shop with an advertised "special".
That is the best way to avoid unnecessary time, parts, labor to deal with this sort of an issue.
Roland