Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › Rich (negative long term fuel trim) causes › Reply To: Rich (negative long term fuel trim) causes July 6, 2023 at 11:10 am #1025331 Taylor MauldinParticipant The map is reading correctly. 29.4 inhg map atmospheric – 8.0 map at idle= 21.4 inhg vacuum