Need help diagnosing this code. It is Fuel Trim Lean on Bank 1. Both intake boots have been changed within the last 2 years. Valve cover and gasket within the last year. Post Cat O2 Sensors also replaced in the last couple of years. Replaced the O-Ring on the DISA and tested the DISA for vacuum a couple of weeks ago. I am going to clean the ICV and Throttle Body in the next couple of weeks but not sure what else to do except order a new MAF.