I have a 2000 GTP, and out of nowhere today the car has started bogging down at 3k RPM when under moderate to heavy acceleration. Once it gets passed that 3k barrier it accelerates like normal. Gear, or speed are irrelevant, just right at 3k it starts to labor. No stalling, or difficulty starting. No SES light either. Any thoughts on possible cause, or where I should start looking?

Thanks,
Steve