I'm currently in week 3 of P90x and I was wondering if I can lift weights on days such as Kenpo X or Back/Chest after working out with Tony. I'll be doing arms/shoulders/chest weight lifting. Is that alright or should I stick to the P90x program plan and forget about any additional weight lifting? Thanks.

You can if you really really want to, but the reason why they have the strength workouts spaced apart is your body needs the break. You really don't get much more gain in weightlifting after 3 days a week of lifting. I would just stick the program and if you're really motivated just up your weight and push yourself that way.

I with with Corp t. I think that id if you feel that you have not gotten the best workout think you need. I would add some of your own sets to get the workout you need. I wend to the gym last week after one workout an lifted some good weight on bicep and shoulder. I knew after that workout, I was done!!

Good Luck!

If you feel you can do wieghts on non-weights days you may not have been bringing it on the "real" weights days.
Resitance training tears your muscles apart - literally. On a microscopic level. You get stronger when they grow back and repair themsleves. If you do't allow time for that you will not get stronger and may even get weaker! Folow the programme as close as you can would be my advice. At least on the first 90 days. Give it a fair shot.

i wanted to do the same thing... but , what to many , that to much...
thanks to my trainer , he created me a programm which i need :

10 min - bike
30 pushups
30 sec jog
15 pull ups
30 sec jog
+ 30 crunches
5 min bike
no breaks , this is everything you need, nothing hard

i repeated this 3 times , and then i do some lifting.. 4 example

monday @ p90x - muscle day , that means only this program no lifting + stretching 1 hour , maybe some jump robe , and martial arts...
that means ,i got ''muscle'' and ''cardio'' day in one. If there is a cardio day ( kenpo x , plyo and yoga ) i do some lifting after that program , i trained only 1 muscle group - 3 exercises ; 3 sets ; 6 - 10 reps

I suggest you go to the gym at first , do p90x in the evening