No, that code was not there before, it seems that all the other codes have gone away (after i replaced the MAF and cleared the codes) and they have yet to return. I will inspect the wiring for damage.
from the wiring i can see, it all looks good. Nothing frayed or missing. I’m also getting a reading from the MAF sensor on my scan tool i couldnt tell you if its a good reading or not but its getting a reading. Like around 200 cfms…
Is that 200cfm at idle? That is way high. I used my scan tool on my 2000 Explorer with a 4.0L V6, and it was reading 35cfm in neutral at idle, 650 RPM. I had to rev up to 2500-3000 RPM to hit 200 cfm. You may have a circuit problem to the MAF.
Here is some data:
From a cold start, i let the car run for about 15 minutes
IDLE:
Long term fuel trim (LTFT): 1.6%
STFT between -5 and +5%
MAF 23cfms and 2.8g/s
throttle 18.4%
load 11.8%
o1 and O2 sensors vary between .1 and .9
vol eff 55%
volts(ad)13.1v
in park with my foot depressing the gas to produce 2500 RPMS
LTFT: same
MAF 85cfms and 10.5g/s
throttle: 32%
load 20% (maybe 28% but my 0 is sloppy)
O1 and O2 are the same
vol eff: 52%
volts(ad) same
3500 RPMS:
all the same except
MAF 170cfms
LTFT 3.1%
So it seems to be running great so i took it for a drive and it ran great until i came stop sign and then accelerated to about 60mph the the symptoms came back. The car losing speed and accelerator unresponsive so i pulled over and wrote down some more values
MAF 3.5g/s
throttle 19%
O1 and O2 same between .1 and .9
LTFT -7%
volts(ad) 12.7
vol eff 53%
then when i put the car back in gear and started to drive home it would not accelerate past 30 mph and the RPMS bounced between 2000 and 2500 i did my best to write down the values
MAF between 300 and 350cfms and 25g/s
01and 02 both steady at .9
stft between 0 and -20%
ltft between -5 and -18%
Both oxygen sensors steady at 900 millivolts
stft and ltft subtracting roughly 20% fuel
You’ve got a very rich condition . . . or at least the PCM thinks you do
What’s your fuel pressure?
What condition is your air filter in?
I think it’s possible the MAF is contaminated and/or faulty
Here’s an idea . . . unplug the MAF and drive the car. The PCM will use default values. If the car behaves much better, the MAF may indeed be faulty
Considering the cat may be plugged . . . has anybody measured backpressure?
What is the rear oxygen sensor reading?
Is it fluctuating at the same rate as the front sensor? It shouldn’t be
Just more food for thought . . .
So…here is what i did. I poured 1 gallon of lacquer thinner into my tank (i estimated that i had about 9 gallons of fuel left). And ran the tank out. This morning, all the symptoms are gone! Also here is a screenshot of my STFT and LTFT which was previously around -20%
So...here is what i did. I poured 1 gallon of lacquer thinner into my tank (i estimated that i had about 9 gallons of fuel left). And ran the tank out. This morning, all the symptoms are gone!
Call me skeptical but I think some ones been watching too much YouTube.
Ha! nice to meet you Mr. Skeptical. I did watch this on youtube, and, I took a chance. So far today it has been running better. I wont say it’s running great. But, i drove 60-65 all the way to work (14.5 miles) and back with no symptoms, and no loss of power.
Cfm probably means cubic feet per minute of measured airflow. It looks like the computer is confused and doesn’t know how to resolve the readings it is getting from the sensors. Fuel trims of -20% mean the ECM is forced – due to the richer than expected O2 sensor readings – to reduce the amount of gas injected by 20% of what it thinks it should be injecting for that operating condition (MAF, throttle position, coolant temp, etc readings). And still that isn’t enough of a reduction, as the O2 readings continue to say there’s a rich condition present. Either there is something preventing free flow of air into and out of the engine or there’s a fuel injection system problem or one or more of the sensor readings must be bogus. Since the active code is for the MAF, it makes sense to start by following the service manual procedures for checking that sensor and its associated circuitry.