Hello all! I was recently given a non-running 89 4x4 van and have been restoring it. With lots of help from this forum I’ve got it up and running at last! During the process I discovered that the ecu is not original and came from an earlier model year. The part number on it is mostly illegible but it ends with a zero where as mine (89 automatic California 4x4) should end with a 1. Before I got the codes cleared it was throwing a 2 and an 11 which proved to be accurate, so clearly an 86-87 ecu. So here is my question! The van seems to be running perfectly. Is there any advantage to spending $300 for the correct ecu? Any disadvantage to going back to the stock ecu such as problematic ca emissions stuff? Any advice or wisdom would be greatly appreciated!