I just recently purchased an 87 Turbo T from the original owner. The car runs and looks good and seems to be well taken care of. It has no modifications whatsoever, and all the maintenance has been taken care of by the Buick dealer. The check engine light is on, and upon scanning the computer, it revealed code 42. It has been my past experience with n/a cars that code 42 usually means bad module, ecm, or faulty wiring. I started off by replacing the module(original unit). No luck, the light is still on after clearing the code. Is the next logical step replacing the ecm? Or am I barking up the wrong tree? Any input would be greatly appreciated.