I recently acquired an F4 which came with a full Arrow exhaust and "performance" ECU. When I took possession, the exhaust and p-ECU were removed and the original parts were reinstalled. Unknown to me, turns out the p-ECU is still in the bike and I have the original ECU (in other words, I possess both). The dealer told me there was no difference between the p-ECU and stock ECU. Is this true? Also, how can I tell the difference between a "performance" ECU and stock? As a corollary, the bike runs fantastic.