2006 Jeep Liberty P0171 DTC: Both Banks Lean - Vacuum Leak or MAF Issue?
Hello, My 2006 Jeep Liberty has recently triggered a P0171 diagnostic trouble code (DTC), indicating both Bank 1 and Bank 2 are running lean. The vehicle ran smoothly until yesterday, when it began exhibiting rough idling and poor performance. I’ve heard that P0171 is typically associated with the Mass Airflow Sensor (MAF), but my Jeep Liberty does not have a traditional MAF sensor—does this mean the code might be misinterpreted or unrelated? The fuel filter in this model is generally non-serviceable, though replacement parts are available. Should I clear the code and monitor for recurrence? The current drivability issues suggest the problem is real. I plan to rent a fuel pressure gauge to check for inconsistencies. While it’s unlikely both oxygen sensors are faulty simultaneously, I’m considering vacuum leaks as a potential cause—especially since both banks are reporting lean conditions. Any advice on troubleshooting this P0171 code in a 2006 Jeep Liberty with no modifications? Thanks for your help.
P0171 does not typically affect both banks simultaneously—this is an important point. I suspect this may be a 3.7L engine, which is common in the 2006 Jeep Liberty. Are you running stock components with no aftermarket modifications or performance parts? Any other diagnostic codes present? Are there any drivability issues beyond rough idling? Start by inspecting for vacuum leaks on Bank 1—this is a common cause of lean conditions and should be checked first.