OBD-I Swap for Later Models

To make tuning later model (OBD-II, 1996-1997) LT1 engines cheaper and easier, it is trivial (at least in the case of manual transmission cars) to convert them to OBD-I EE ecms so the techniques listed here will work.

Tuning software for 1996-1997 engines is fairly expensive, and due to the lack of research into them, can sometimes be missing many critical parameters.

You will require only an ECM from a 1994-1995 LT1 (the model of car is not important), and the appropriate knock SENSOR for that car (which screws directly into the block).

The pinouts are identical, and no changes to wiring need to be made.

After swapping for an OBD-I ECM, the following unnecessary electrical parts will be non-functional, and can be safely removed:

  • The vacuum sensor for the CCP near the passenger fuel rail
  • The crankshaft position sensor
  • The rear oxygen sensors

Some datastream information to peripheral devices such as the body control module may no longer work, however I have done this swap many times without issue.

Automatic transmissions may experience PWM lockup problems, as well as other issues from differences in transmissions, so I reccommend this swap for manual transmissions only.