Hello, I hope I can be of assistance.
Is the engine running smoothly or does it judder when you accelerate? Are no warning lights showing?
Let me know and I'll reply as soon as I'm able to.
does not judder at all and no warning lights on just slow on picking up speed
does not judder at all and no warning lights showing takes time picking up speed
the most common cause of a lack of power on this model is usually caused by a misfire due to an ignition coil failure. Normally this would result in a judder though. Check that the output from the coil is OK using a pair of nylon pliers or if possible a scope to check the firing voltage and spark duration.
If the car has had a misfire previously it is possible for the catalyst to block up so not allowing the engine to breath correctly, this will cause a lack of power.
Other than these common concerns check obvious things such as fuel quality, air filter and fuel filter.
If there is a sensor or actuator control causing this I would expect the engine management light to come on as the PCM is very good at detecting concerns.
Start with these points, especially the ignition coil, let me know if I can advise further and I'll reply as soon as I'm able to.