I have had the same problem on my 1994 Sonoma 4x4 4.3L Vortec on 3 separate occasions. Each time it was due to the EGR valve being stuck in the open position due to a chunk of carbon jamming the plunger in the open position. The 1st time was when I exited the expressway and had to goose the throttle just to keep the engine from stalling. Remove your EGR valve and push in on the plunger to make sure it moves in and out freely.
Your 2nd problem I also had, it was from a bad torsion bar mount. The banging your hearing is the torsion bar hitting the frame when turning. This is not an easy repair because the torsion bar must be removed from the vehicle. Mine was rusted in place.
Monday, May 28th, 2007 AT 3:45 PM