Problems with 2006 Lincoln Navigator ELECTRONIC STABILITY CONTROL

I am having continuous problems with my 2006 lincoln navigator. for a vehicle of this quality, i never dream of so many problem. i had my suspension system fix last year at the dealer. 1 year has pass now it is gone out again. i had my catalyst converter fix at the dealer about 2 years ago. 1 year later they are gone out again. now i am riding around with a bouncing navigator and a sluggist running navigator with plenty of fumes. i just don't have the funds for continuous repairs for the same service. do the mechanics know what they are doing? i am really frustrated with this vehicle and the service i have received. bouncing around in a 40,000 + vehicle is embarrassing. please help. i have to bum a ride at time. i have to travel , a lot and rent a car. this is getting old and expensive. the dealer want fix it because they say it is out of warranty, eventhough i have paid to have it fixed before. this is not costumer service. help! *tr

(1) traction control system failure (4) plus times. (2) brakes began to pulsate, the wheels starts to grip and grind to make a traction adjustment and the engine starts to stall. the traction control system activates during normal driving conditions.(3) dealer service manger reuben fernandez at freeway lincoln dealership in california has tried to duplicate the condition and has not been successful in doing so. the dealer's service request that i drive the car until the condition worsens before he can fix the problem. the suv's computer was adjusted and reset. the failure has accrued twice since then. the dealer currently has the suv and iv'e requested the car be replaced by ford. *nm