What is a FCON?

PFC - Programmed Fuel Computer (also PF-CON, FCON)

With ECMLINK, this is to be avoided and is here for archival prupose only.

HKS sells this "piggy-back" computer, and its purpose is to fool the stock ECU into delivering more fuel under certain conditions. It's important to note that this "piggy-back" computer (as they call it) does not exactly work *with* the stock ECU the way that HKS ads might lead you to believe. The PFC doesn't share any data or address lines with the ECU, the only connection it has is thru the lines that originally ran directly to several engine sensors. By altering the signals from these engine sensors, the ECU is "fooled" into delivering an different quantity (usually more) of fuel.

There are limitations with this system, because the factory ECU it still is in final control and has the same limitations.

It should NOT be viewed as a substitute for an self-contained engine computer/control system. A true aftermarket engine control computer will provide vastly greater function and flexibility. The major advantage of the PFC-FCON is that it is fool-proof and very easy to install.