Mazda 6 - 2006 - Lack of Acceleration/Gas Pedal not funtctioning.

I have a 2006 Mazda 6.  Back in 2008, would start car up (5 speed), back up , go forward and anti lock lights and other dashboard lights come on, pedal to the floor, will only go 30 mi per hr.  Turn the car off.  Turn it on...runs like normal.  After several visits to the dealership, replaced throttle body.  Worked fine for about 3 years.  Then, it started again.


Lived with it as it would happen infrequently.  Took it to my mechanic.  Replaced the pedal, replaced sensors.  OK for about 6 months.  No issues.  Then starts happening again - exact same scenario.  Turn it off, turn it on...runs fine.

As time goes on, happening more frequently in summer months (heat here in AZ more noticeable).  The car is now my son's.  has about 130K miles on it.  A wonderful car - outside of this issue.  It has progressively come back but was usable.  Happened infrequently.  Then it progressively got worse.  Have had several visits to private mechanic.  Have replaced the throttle body with a used one, have replaced (rebuilt) the computer.  24 hrs good, then went back to doing the same thing.  Now, you can't even get out of the garage.  Starts up fine but no registration to the gas pedal at all now.  Had to tow it to my mechanic.  HELP!