1995 pontiac bonneville, 170k miles, 3.8 liter V-6, automatic check engine light came on about 1 month ago have had it in several shops and computers all read "link error" it is sputtering all the time still drives and goes just not the pick up it did have and the dash light go out when the headlights are turned on, I have replaced the starter, water pump, cam sensor, fuel pump and given a basic tune up - plugs, wires, belt, transmission fluid & filter. Please help I like this car and would like to keep it need it to stay running or is it worth the effort?