If i have a stress can i still take a focus using this card ?

Thanks for any answers.

No. Having a stress still prevents you from taking Actions. What Pattern Analyzer does is move the step where you would gain a stress from making a red manuever to after the Perform Action step, so that if you didn't have stress to begin with you can make a red maneuver and perform an Action before gaining the stress from it. It does not give you Tycho's pilot ability.

It's worth noting that moving the Check Pilot Stress step after Perform Action allows two different effects. Otacon listed the first, and the other with Push the Limit allows you to reveal and execute a green maneuver, do your action, PTL an action bar action, gain a stress, and then lose it.