bank 2 - rich, bank 1 - lean and stumbling master techs
#1
08-09-2010, 07:56 PM
bank 2 - rich, bank 1 - lean and stumbling master techs
So I've be struggling with this for a couple months.
As the title says, the PCM is throwing codes saying bank 2 is too rich and bank 1 is too lean. I have an aftermarket K&N intake installed, which is what ford is blaming, however that was on for a solid two years prior to seeing any issues.
A diagnostic shows long term bank 1 at 28.1 and bank 2 long term at -28.9. I have replaced the MAF sensor. It is giving a reading of -.25 to .5V lower than it should be, according to some table at Pepboys, for the given amount of airflow. The new sensor immediately was also giving a low reading. I attempted to disconnect the MAF, which supposedly puts the vehicle in FMEM mode, and it hasn't yet thrown a code, but judging by the way it's running, I assume it will.
Idle is poor, and seems to be missing. Acceleration lags from time to time. Under WOT, performance seems as amazing as ever.
The master tech at pepboys said my O2 sensors were giving fine readings.... And recommended I take it to ford and have them recalibrate my PCM?
I know ford is going to have me put a stock intake on it before they even do any real troubleshooting. Anyone have any ideas?
Thanks
As the title says, the PCM is throwing codes saying bank 2 is too rich and bank 1 is too lean. I have an aftermarket K&N intake installed, which is what ford is blaming, however that was on for a solid two years prior to seeing any issues.
A diagnostic shows long term bank 1 at 28.1 and bank 2 long term at -28.9. I have replaced the MAF sensor. It is giving a reading of -.25 to .5V lower than it should be, according to some table at Pepboys, for the given amount of airflow. The new sensor immediately was also giving a low reading. I attempted to disconnect the MAF, which supposedly puts the vehicle in FMEM mode, and it hasn't yet thrown a code, but judging by the way it's running, I assume it will.
Idle is poor, and seems to be missing. Acceleration lags from time to time. Under WOT, performance seems as amazing as ever.
The master tech at pepboys said my O2 sensors were giving fine readings.... And recommended I take it to ford and have them recalibrate my PCM?
I know ford is going to have me put a stock intake on it before they even do any real troubleshooting. Anyone have any ideas?
Thanks
#2
08-10-2010, 10:10 AM
You could see if there is anyone else besides a Ford dealer in your area that does vehicle tuning. If you live in an area that has a bit of population odds are you could find one with some digging. Maybe the Ford dealer will tell you where one is...
You should also let us know what year and engine size you are dealing with.
You should also let us know what year and engine size you are dealing with.
#3
08-10-2010, 10:27 AM
Its a 2003 F150 Supercrew with a 4.6L V8 and 75k miles.
Is tuning an old PCM really necessary though. It seems as though the MAF mappings are off, but I just don't understand how that could happen. Does the PCM "learn" these incorrect mappings over time?
Would an off the shelf performance tuner be able to remap this with the factory default correctly? I've been looking for an excuse to buy a predator anyways.
Also, do PCMs actually get updated with new software from time to time by the dealer? If so I guess there probably isn't anyone else that could update it.
Is tuning an old PCM really necessary though. It seems as though the MAF mappings are off, but I just don't understand how that could happen. Does the PCM "learn" these incorrect mappings over time?
Would an off the shelf performance tuner be able to remap this with the factory default correctly? I've been looking for an excuse to buy a predator anyways.
Also, do PCMs actually get updated with new software from time to time by the dealer? If so I guess there probably isn't anyone else that could update it.
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