Oldsmobile/Buick Repair: 95 buick lesabre ECM problems?, buick lesabre, weird problems

Question
Hi Van Our car (95 buick lesabre) has some weird problems.  
When you hit the gas the engine hardly revs up and it doesn't seem like it wants to shift gears correctly.  Also when you put it into park or neutral the engine will rev up on its own.   
When at first the gears where not shifting correctly we thought it was the transmission we gave it a transmission flush and still 1 year latter it has these problems?
 Someone suggested that these problems may be because of the ECM.  Do you think that this may be the case? And if so how do i go about Testing it? And can i just get a new one and replace it?

Answer
Hi Brandon,
Before replacing any expensive parts, get a new fuel filter, and borrow a fuel pressure tester from Autozone, and make sure the fuel pressure is where it should be.
I believe about 45PSI on that, but literature with the tester should say.

Van