System too lean code on 96 chrysler town and country 3.3 car has a bit less power and is burning fuel rapidly (12-15 mpg highway) norm is 21-24. Problem comes and goes, I already tried to add fuel system treatment to each fill up not much help. What to do?

Po171 is a lean code.
Miscalibrated 02 sensor-- exhaust leak
intake vac leaks or incorrect map valve
or low fuel pressure/volumn.

Used 2003 Lincoln Town Car Consumer Reviews ' Edmunds

www.edmunds.com > ... > Town Car > 2003 Town Car
Edmunds.com Rating: 4.4 - ‎64 reviews
Nov 23, 2012 - View all consumer reviews for the 2003 Lincoln Town Car on Edmunds, ... This car gets 29 to 30 mpg on highway with ac driving at 60 mph.

yes you need a new thermostat or there is low coolant. this will affect the mpg because your overheating and thats why its stalling. dont drive until you fix or you will blow your head gasket if it isnt blown already. change thermostate and check coolant.

that is your idle air control valve . it is located on the throttle body next to the throttle position sensor

carburetor needs cleaning, your jets are probably clogged. replace fuel filter (inline) and check egr valve

DTC P0171 - System Too Lean (Bank 1)
Basically this means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC (Diagnostic Trouble Code) is very similar to P0174, and in fact your vehicle may show both codes at the same time.

I would suggest that you take a look at the front oxygen sensor. Typically speaking the oxygen sensor causes this code to appear. Here is the possible cause list from the manual for your car.

Trouble Code: P0171 (2.5L V6 Auto) - Fuel System Lean (Bank 1)

Possible Causes:
Air leaks in intake manifold, exhaust pipes or exhaust manifold
Base engine mechanical problem causing a lean A/F condition
Fuel control Sensor is out of calibration (e.g., ECT, IAT or MAP)
Fuel delivery component fault (clogged filter, low fuel pressure)
O2 element is contaminated, deteriorated or it has failed
Vacuum hose is disconnected, broken, leaking or loose

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P0171 is a "System too lean - Bank 1" code.


Pretty much means that an oxygen sensor in bank 1 detected a lean condition (too much oxygen in the exhaust).

You might not notice drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.

Causes:

• The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
• There could be a vacuum leak downstream of the MAF sensor.

Possible solutions include:

• In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
• Inspect all vacuum and PCV hoses, replace if necessary
• Check for a dirty fuel filter and proper fuel pressure

P2096-DOWN STREAM FUEL SYSTEM 1/2 LEAN

If you gotten gas might have been a bad batch, I would find a way and reset the light, once you reset the light by clearing the codes you will need to complete the DRIVE CYCLE which will then tell you IF the light returns there is a problem with the O2 sensor or you are having Fuel problems.

You need to run it though cool down test. I'll look it up and repost.

i had same toublre on 96 plymouth output speed senor my wont shift out of second