V6 96' Shuttering Problem

[GRANDE,GRANDE!!]

Ive never had any major problems with my Grande since i bought it, its been the perfect car, until recently something has me a little worried.

It seems that sometimes my car seems to shutter as in drop revs a little bit occasionally (usually when i havent started it for a couple of days) but this problem never worried me that much as the shuttering would go away after a while. But today something happened thats got me confused.

I was in a little bit of traffic strife as i was coming home from work and i had to basically put the foot all the way down to avoid an accident from take off.

Anyway when i did this i noticed that my camry was shuttering extremely. The best way to describe it would be like the pedal felt tho as it was sticking. Physically i know this did not happen as i looked down and theres nothing wrong with my pedal.

The car from take off to about 3000RPM runs fine, but after that it begins massive shuttering and it feels like it cannot reach the speed without dropping revs and gaining while foot is down all the way. Basically, with the foot down, it cannot reach the end of the gear without sticking at multiple points.

I tried while stationary to put it into P and rev it out. It was fine. So i am real confused as to what it might be.

If it makes any difference:
I had not started the car up in almost a week
Petrol was extremely low (allthough i filled up on the way home after i had the incident and tried it again a few times and no difference)
Spark plugs have not been changed in god knows how long
Timing belt hasent been changed and its almost approaching 200,000Kilometers

So basically to sum up, the car wont reach second gear while the foot is down completley without displaying some sort of shuttering and struggle.

Does anyone have any suggestions on what this might be?
Has anyone experienced similar problems?

[Kep]

If you search around you will notice that I almost always propose cleaning out the emissions system first and then going on from there. I would focus on the throttle body and EGR system in your case. Also clean the PCV valve just because it is easy. If you remove the throttle body it gives you better access to the EGR valve and since it is out you can clean the IAC valve below it. If you don't remove the throttle body, squirt some cleaner down the diagonal hole into the IAC valve to help clean it. Use throttle body safe cleaners where necessary. Check your air hose for cracks.

Does it happen the same whether cold or hot?

Kep