help

frst when under load between 2500-3000 rpm it shuts down a cylinder and missfires had it on code reader it came up fault code 37 map cicuit fault have fit a new map sensor and checked wiring but all ok

have checked through rest of wiring and sensors and all seem ok has anyone any ideas before we try to source a ecu

ps was chipped but have unplugged it and let it remap itself but still same

many thanks pop