Ok, i got a little problem with the ignition system on my 89, i keep getting a code 43 which is ESC bypass/failure. I dont really care about the check engine light or anything, but when it comes on my truck runs like a 305 and sucks gas. So far ive replaced the knock sensor twice, the knock sensor harness once, and the ESC from an 89 burban. Im going to try an ignition module this weekend. Anybody know whats wrong with it? If it helps i have access to a GM Tech 1, and i have the factory Fuel and Emmisions/Driveability manual for my truck. Thanks in advance.