The original '96 Passat ECU's are distinguished by their black plastic case and the part number ending in "BK". If you have one of these, your tuning options are very limited, because of the older 8-bit architecture and internal 2-bar map sensor (boost pressure sensor) that limits available boost to 14.7 psi.These original "BK" ECU's were replaced with a newer, metal case, "GQ" ecu as part of the "smoke recall" campaign on these early passats. Later passats came standard with a metal case "FA" model ECU, which will also work in the early Passats. The "metal case" ECU's respond much better to tuning than the plastic ones, so this is a popular upgrade for the early Passats. We have a limited number of used "metal" ECU's available, that are suitable for use in a '96 Passat - or any car with an AHU engine. The price includes your choice of either tuned or stock ecu chips. Please call or e-mail to confirm current availability.