1997 blazer 4.3, 4-wheel drive. SES light on with codes P0171, P0174.
Have cleaned the MAF, installed new air filter(stock, not oiled), no vacuum leaks, new fuel filter, new engine coolant temperature sensor, cleaned IAC valve. cleaned throttle body, no exhaust leaks. Have sprayed starting fluid around upper plenum and around lower intake manifold gasket area (old trick), but idle did not change. Car idles rough in gear and will eventually stall. Any more ideas? Great site by the way. I have read many posts on this, but I still have not solved this issue.