My 98 4.2L shakes very harshly from time to time. It happens after I drive on the highway for 2 hours between home and college. When I come to the first or second stop after leaving the highway, the whole truck shakes like it's in an earthquake! The way I get it to stop is press on the brake and rev the engine for about 10 seconds. It use to happen once every month or two but it has happend like 4 times in a row now. However, just before I drove back today, I put in a bottle of Redline Fuel Cleaner and it didn't happen when I got here. Is it the vaccuum or fuel injectors being out of whack after having my foot on the gas for 2 hours straight? Does anybody know what is causing this or have it happen to them? -Thanks

 

Check the 02 sensors on the truck.