Lately I noticed a little hesitation at high speeds. any suggestion as to what could be the cause of this. I would like to fix it over the wknd

 

So you have a fuel leak....
Fire!!!!!
stop driving!! Or boom!!! Fire!!!
Gas....hot items....
what are you asking?!
If your injector is leaking, and you have a hesitation...it may/maynoy be related....but if the car burns, you will never know....

 

In that case the car will be parked. My car has 146xxx on it. Should I change out all the seals and injectors?

 

Depends what the problem is...
If an oring is bad...than a oring will fix it...if an injector is cracked...then a,new injector would be needed...
With lots of miles, it could be lots if things...just have to take it appart, fix the cause.