Intermittent lack of power and low idle
So here's the history...
Starting about a week ago my little Ranger starting occasionally losing power and running roughly on an occasional basis. Often it would come on as I was going down the freeway at 70 mph.
Over the last week using my manuals and web forums I have replaced the MAF, IACV, air filter and fuel filter. I have checked the PCV and the rubber elbow hose. I can't hear any leaking vacuum hoses.
My ODB II reader has at various times given me P1131, P1151, P1071, P1074 codes. The last test run I made got me P0136 as well as P1131 and P1151.
The odd thing is that it's intermittent. The lack of power and roughness will come on suddently and then if I just chug along it will correct itself and run properly for a few miles before doing it again.
4.0L 5 Sp Manual