Help: P0171 System too Lean (Bank 1)
#21
I found a new site that some might like, it looks good, does anyone here subscribe to Identifix?
http://identifix.com
The Direct-Hit feature looks like what I am interested in, and could help greatly with this troubleshooting...
Here's what it says on a 2001 Dodge Durango 5.9L (the only car you can view for the free trial)
P0171 Fuel System Lean (Bank 1) & P0174 Fuel System Lean (Bank 2)
Possible Causes
* Base engine mechanical problem causing a lean A/F condition
* Check for air leaks in the Air Induction system (e.g., in the intake manifold)
* Check for air leaks in the exhaust manifold and in the exhaust pipes
* Fuel control sensor is out of calibration (e.g., ECT, IAT or MAP)
* Fuel delivery component fault (clogged filter, low fuel pressure)
* HO2S has failed (it may be contaminated with fuel, silicone or water)
* Vacuum hose is disconnected, broken, leaking or loose
Setting Conditions
Engine running in Closed Loop; IAT sensor signal more than 20ºF, altitude less than 8,000 feet, and the PCM detected too large an amount of Fuel Trim correction existed due to a lean A/F condition.
This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
http://identifix.com
The Direct-Hit feature looks like what I am interested in, and could help greatly with this troubleshooting...
Here's what it says on a 2001 Dodge Durango 5.9L (the only car you can view for the free trial)
P0171 Fuel System Lean (Bank 1) & P0174 Fuel System Lean (Bank 2)
Possible Causes
* Base engine mechanical problem causing a lean A/F condition
* Check for air leaks in the Air Induction system (e.g., in the intake manifold)
* Check for air leaks in the exhaust manifold and in the exhaust pipes
* Fuel control sensor is out of calibration (e.g., ECT, IAT or MAP)
* Fuel delivery component fault (clogged filter, low fuel pressure)
* HO2S has failed (it may be contaminated with fuel, silicone or water)
* Vacuum hose is disconnected, broken, leaking or loose
Setting Conditions
Engine running in Closed Loop; IAT sensor signal more than 20ºF, altitude less than 8,000 feet, and the PCM detected too large an amount of Fuel Trim correction existed due to a lean A/F condition.
This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
Last edited by libertyforall1776; 11-17-2009 at 07:19 PM. Reason: Added Identifix details
#23
I'm trying to figure out how to check it with freeze frame data, so not yet.
The shop said they couldn't reproduce the SES (I find it hard to believe, but possible). So I need to find out what conditions tend to trigger it, or show other proof. I have an extended warranty that covers O2 sensors, so naturally I don't want to pay for them myself. ;-)
The shop said they couldn't reproduce the SES (I find it hard to believe, but possible). So I need to find out what conditions tend to trigger it, or show other proof. I have an extended warranty that covers O2 sensors, so naturally I don't want to pay for them myself. ;-)
#24
It's an O2 sensor k? Try triggering it like this... Dunno if you're auto or manual. But get onto the highway and when you start to speed up, once you hit 3rd in your auto or 4th in manual, hold that gear all the way to 75 before you shift. Just don't try flying thru the gear. If it's an O2 that may possibly trigger it.
#25
Automatic...
It's an O2 sensor k? Try triggering it like this... Dunno if you're auto or manual. But get onto the highway and when you start to speed up, once you hit 3rd in your auto or 4th in manual, hold that gear all the way to 75 before you shift. Just don't try flying thru the gear. If it's an O2 that may possibly trigger it.
#27
thats a new one for me evil i would just get under there and check the wires to the o2 sensor i had my driver side some how rest on the exhaust pipe and melt the wires... that was a mess but if you quit clearing the codes liberty they can pull up the code even if the check engine light is no longer on.... codes stayed stored in your vehicles memory until cleared even if they are inactive
#28
Yeah well you never know it could just be the sensor itself going bad or getting bad readings from burnout :P No physical markings then. Consistent high RPM load is what will trigger a misfire from O2s because the engine is requiring more fuel but the O2 reading is all whacked out.
#29
Not quite, because they need to get the code to set when they are checking the car because otherwise they cannot use their Tech 2 to further analyze the freeze frame & failure record for the root cause...
thats a new one for me evil i would just get under there and check the wires to the o2 sensor i had my driver side some how rest on the exhaust pipe and melt the wires... that was a mess but if you quit clearing the codes liberty they can pull up the code even if the check engine light is no longer on.... codes stayed stored in your vehicles memory until cleared even if they are inactive
#30
Ok, but I currently get ZERO misfires, just the two lean codes...
Yeah well you never know it could just be the sensor itself going bad or getting bad readings from burnout :P No physical markings then. Consistent high RPM load is what will trigger a misfire from O2s because the engine is requiring more fuel but the O2 reading is all whacked out.