CEL Mystery. Fuel Trim Reading Help!
11-27-2018, 05:21 PM
#1
Junior Member
Thread Starter
CEL Mystery. Fuel Trim Reading Help!
2010 F-150 Lariat Supercrew 4x4 206k Miles
I have the dreaded P0130 and P0150 CEL still showing up after clearing it multiple times. I have cleared the MAF sensor already and checked everywhere for vacuum leaks. Nothing is showing up. Using my SCT X4 Tuner, I focused on the Short Term and Long Term Fuel Trims and found them to hover right around 1.0. LTFT moved from 0.99 to 1.0 with an occasional 0.98 showing up. STFT went as low as 0.88 and as high as 1.14 but always comes back to 1.0. To me, this shows no lean or rich conditions, correct? Yet I still have the pesky CEL on. I know there is a TSB for this but I don't think it is simply in the tune. But yet both upstream O2 Sensors going bad at the same time seems like I won the lottery...The lottery no one wants to win... Am i missing something or should I just dive in to replacing the O2 Sensors and see if that fixes it? Or go to the dealership and have them update the vehicle tune per the TSB?
I have the dreaded P0130 and P0150 CEL still showing up after clearing it multiple times. I have cleared the MAF sensor already and checked everywhere for vacuum leaks. Nothing is showing up. Using my SCT X4 Tuner, I focused on the Short Term and Long Term Fuel Trims and found them to hover right around 1.0. LTFT moved from 0.99 to 1.0 with an occasional 0.98 showing up. STFT went as low as 0.88 and as high as 1.14 but always comes back to 1.0. To me, this shows no lean or rich conditions, correct? Yet I still have the pesky CEL on. I know there is a TSB for this but I don't think it is simply in the tune. But yet both upstream O2 Sensors going bad at the same time seems like I won the lottery...The lottery no one wants to win... Am i missing something or should I just dive in to replacing the O2 Sensors and see if that fixes it? Or go to the dealership and have them update the vehicle tune per the TSB?
11-29-2018, 06:02 PM
#2
LightningRod
I could only suggest that - those DTC are "CIRCUIT" related. I would check the wiring from the PCM to the O2 sensors very well for shorts / opens / poor connector connections before replacing the O2's.
I also believe that, given that neither O2 sensor is able to produce a valid reading - I would have NO faith in the Fuel Trim readings. The PCM uses a concept called FMEM (Failure Mode Effects Management), and those fuel trim readings may be defaults JAMMED in to keep the truck running as best as it can.
Get rid of the P0130 and P0150 - however you have to.
I also believe that, given that neither O2 sensor is able to produce a valid reading - I would have NO faith in the Fuel Trim readings. The PCM uses a concept called FMEM (Failure Mode Effects Management), and those fuel trim readings may be defaults JAMMED in to keep the truck running as best as it can.
Get rid of the P0130 and P0150 - however you have to.
11-29-2018, 08:45 PM
#4
Junior Member
Thread Starter
I could only suggest that - those DTC are "CIRCUIT" related. I would check the wiring from the PCM to the O2 sensors very well for shorts / opens / poor connector connections before replacing the O2's.
I also believe that, given that neither O2 sensor is able to produce a valid reading - I would have NO faith in the Fuel Trim readings. The PCM uses a concept called FMEM (Failure Mode Effects Management), and those fuel trim readings may be defaults JAMMED in to keep the truck running as best as it can.
Get rid of the P0130 and P0150 - however you have to.
I also believe that, given that neither O2 sensor is able to produce a valid reading - I would have NO faith in the Fuel Trim readings. The PCM uses a concept called FMEM (Failure Mode Effects Management), and those fuel trim readings may be defaults JAMMED in to keep the truck running as best as it can.
Get rid of the P0130 and P0150 - however you have to.