Hi i have a ep3 race car with a kpro installed , my car has a forged bottom end , standard head with stage 3 crower cams , ive just installed a skunk 2 plenum and 74mm throttle body , the car will start but wont accept any throttle , having put an AFR meter on it its jumping from very rich (10.6ish ) on tick over , but when throttle is applied it jumps to very lean ( 18+ ) the ECU has now shown a fault code of P1607 and says "ecu internal circuit malfunction , check calibration " . Can you please help and tell me what the fault code means and perhaps how to solve this issue .
Thanks