Thanks for the reply. I have a JDM ecu. I'll check what you suggest. I had reset the ecu to clear codes and the engine light came up again. I expected it to be code 16 again but to my surprise it was code 6 - coolant temp sensor - wtf...the only thing I can think of was I hadn't bled the cooling system after I took off the IACV. But I have now bled the system and reset the ecu and will see what happens.