Guys, my O2 sensors bank 1 S1 and S2 arent switchin across the proper voltage. They are both stuck between 0.030 and 0.060 V at higher rpms (+2500) B1 S1 will start switching properly between 0.100 and 0.900 V.

2001 F150, 4.6 triton, 4x4 supercrew 395,000 km
BOTH Bank 1 sensors are brand new.
The secondary cat has been hollowed out, exhaust leaks fixed.
THe B2 sensors sometimes switch normally sometimes stick between .800 and .900 V but never drop out to these levels way below .1 V that the bank 1 is doing.

Trying to pass an Etest here and have replaced most sensors and hosing on the truck. Cleaned out a lot of blockages within the intak manifold and components as well. Several drives above 50 km as well

I'm getting lack of HO2S11 and lack of HO2S21 codes and constantly a B1 S2 sensor circuit code. Again I can get S1 to start switching under RPMs or driving conditions but never S2`. I've also added a heavy gauge additional ground at the neg. terminal to the manifold.

I'm thinking electrical or PCM, I'm working on a replacement PCM but can anyone direct me where to start on tracing the electrical harness resistance, voltages, shorts etc.

Or any other alternate suggestions to these low B1 voltages would be greatly appreciated.

 

Post the actual fault codes, not the descriptions....

 

Codes its throwing are P1131, P1132, P1152, P0136

I've already trouble shooted most of the possible causes FORD lists for these codes but have obviously overlooked something.

6 out of 10 IM Monitors reset, 2 are unsupported and the Catalyst monitor and Evap monitor won't reset.

Thanks

 

Did you reset the PCM to clear codes then retest? With those DTCs, several of the IM monitors should never have passed.

Have you checked your short and long term fuel trims?

The 1131 and 1132 are contradictory codes.

 

Yes I've reset the pcm dozens of times in this month long diagnosis proceedure.

I realise these codes contradict each other, this is why we are lost in what direction to turn now affter replacing so many engine components

I understand some of the I'm monitors should never have reset, ESPECIALLY the Oxygen sensor monitor this is why we've turned to the internet for suggestions

My other post is regarding PCM replacement as with the eroneous info this is the direction I'm leaning.

The trims at the O2 sensors are running at 99.2 percent on bank 2 and 4.7 percent at bank 1 sensors

The upstream bank 2 cat also gets red glowing hot, which we are also trying to resolve if this is the cat or just because the fuel is so rich on that bank