My truck has the 4.6 Triton motor. I all of A sudden the check engine light up along with rough running and sometimes stalling while coming to A stop. A friends scanner showed multiple codes P2198-02 sensor signal stuck rich bank 2 sensor 1, P0106- map/bp sensor range/performance, P0109- Map or baro pressure circuit intermittent, P0402- egr excessive flow detected. What is strange is my truck is 2006 f-150 STX and doesn't have A map sensor. On the mass airflow sensor wire plug, I have the red lead of my tester on the red wire on the MAS and the black test lead on the black wire, that showed 12.3 volt. I left the red test lead on the red wire and just moved the black test lead to the next wire over 12.3volt, and the next wire over the same 12.3 volt. The very last grey wire toward the driver fender showed 8.84 volt one time, I checked it again it showed 3.67 volt. I moved on to the oxygen sensor wire plugs. All 4 o2 wire plugs I left the black test lead on the black wire, and moved the red test lead to the two white wires, both showed showed 10.0 volts. The grey wire showed no voltage on any of the 4 o2 sensor plugs. I got the same readings on bank 1 sensors 1 and 2 and bank 2 sensor 1. Now bank 2 sensor 2 showed 6.3 volts on both white wires and no voltage on the grey wire. Where do I start? I definitely don't want to waste money throwing mass airflow, and all 4 o2 sensors at it and still have the same problem. Thank you in advance for helpful suggestions.

 

The MAP sensor is integrated into the ESM.

Your voltmeter testing on the O2 wires, as reported, were not valid tests. I have no idea why you'd be probing on the MAF sensor.

You have a SnapOn scanner that costs thousands of dollars. Do you not have also access to the proper diagnostic procedures for those fault codes so you don't have to guess or just throw parts at it?

 

Honestly my friend hasn't had that scanner for very long and he doesn't quite know how to use it to its full potential. Unfortunately no I don't have access to the proper diagnostic procedures. That's why I am here hoping someone will help me out. I was probing on the mass airflow just to make sure I was at least getting voltage there.

 

I figured it out. While I was replacing the rusted leaking transmission cooler lines, I decided to put new power steering hoses on too while I was at it. I bought A aftermarket power steering pressure switch to go with the pressure hose, that was my problem. I simply unhooked the aftermarket sensor and the truck straightened right up. Its going to be OEM Motorcraft parts from now on.