Vehicle is a 2003 Montero Sport LS awd. 3.0 engine auto trans. 196,000 miles.
About 2 years ago I got codes po171 and po174. Lean on banks 1 and 2 as I understand. I replaced the maf sensor. Problem went away until about a month ago. Codes returned. I again replaced the maf sensor. Problem went away for about 2 weeks. Light came back on now showing codes po172 and po175. My understanding is bank 1 and bank 2 are running rich. I replaced the fuel and air filters less than 3000 miles ago.
The truck runs great. No problems at idle, town or highway driving.
I will be thankful for any ideas and things I can check to correct this.