What aftermarket computers (or chips) are available?
A common upgrade among both Japanese and German cars, reprogrammed engine controllers have only come to the Neon recently. The two most common are the AF/X unit ($350, plus exchange) modified by Gary Howell’s development company, and the recently-released Mopar Performance unit ($200-300, no core charge). These computers contain modified ignition and fuel information tables, which the controller uses to vary the spark timing and the quantity of fuel delivered by the injection system. In most cases they also raise the built-in rev and speed limiters. These units are not cheap, but do offer real performance gains, especially in conjunction with other modifications such as intake or flow improvements. For the AF/X unit, various ‘stages’ are available, some of which are not emissions-legal. All of the Mopar Performance controllers are emissions exempt. Also, most will require 92 octane gas or better to prevent detonation or ‘pinging’, which can be very harmful to the engine. The PCM is spe
