98 ford taurus starts, runs, dies

• DTC P0171 Fuel Trim System Lean Bank 1
• DTC P0174 Fuel Trim System Lean Bank 2
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The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without oxygen sensor (O2S) input. During Closed Loop, the O2S inputs are added and used by the ECM to calculate short and long term fuel trim (FT) fuel delivery adjustments. If the O2S indicates a lean condition, FT values will be above 0 percent. If the O2S indicate a rich condition, FT values will be below 0 percent. Short term FT values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term FT makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the ECM detects an excessively lean condition, DTC P0171 or P0174 sets.
Diagnostic Aids
• Excessive resistance in the fuel injector ignition 1 voltage circuit or the fuel injector control circuit may cause the following symptoms:
- Lean condition
- Misfire
- Rough idle
• The system will go lean if an injector is not suppling enough fuel.
• A lean condition could be present during high fuel demand.
• A malfunctioning MAF sensor can cause this DTC to set. Refer to DTC P0101 .
• Review the Failure Records with a scan. If an intermittent condition is suspected, refer to Intermittent Conditions .

DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0420 Catalyst System Low Efficiency Bank 1
• DTC P0430 Catalyst System Low Efficiency Bank 2

This code could mean the catalytic converter on that bank has failed .

Causes of lean condition trouble codes P0171 P0174 GM 5 3L

P0420 P0430 catalytic converter catalyst inefficiency code diagnosis

The recommended repair for both the P0171 and P0174 codes is to clean the MAF sensor. Ensure you use the proper cleaning solution, as there are many that will damage the sensor. Buy a cleaner that is made specifically for MAF sensors. The P0420 code will probably clear up if the MAF sensor clears the other two codes.

looks like its all emission stuff

code p0171 refers to system to lean bank 1==causes intake /exhaust leak--AIR system--MAP/MAF sensor--fuel pressure/pump--injectors--HO2s Have a fuel pressure test done on the fuel manifold to check for blocked filter/faulty pump/fuel pressure regulator faults
code p0174 refers to system to lean bank 2 --same causes including hose connection/s
code p0420 refers to catalytic converter system -bank 1 efficiency below threshold==causes catalytic converter--wiring--HO23. Check the cat converter is not cracked inside and the oxygen sensor is working.

t . You have a code reader ? you need a professional type scan tool that shows sensor data PID's Ford EGR Flow Testing P0401 P0402 P0405

A P0171 / P0174 lean exhaust code could be a plugged filter , vacuum leak , low fuel pressure . Your best bet take it to a qualified repair shop that has diagnostic tool's do diagnose ! Causes of lean condition trouble codes P0171 P0174 GM 5 3L

I would start by looking for a broken vacuum hoses. That would cause 2 of the codes. The other 2198 is stating that the o2 is stuck rich. Look for the vacuum leak and let me know when you have that or if you do not find one.

p0171 and p0174 are o2 sensors, There are 4 o2 sensors on a Taurus. 1 on each exhaust manifold, and 1 after each catalytic converter.
p1518 is vehicle speed, idle speed control----this means the idle air control needs fixed. you can take it off and clean carbon from it. do not push on end of air valve it will loose its adjustment. do not put in any liquid to clean, the best way is to clean end of valve with an old toothbrush or similar. also clean carbon from engine side where iac mounts. when clean put back on. you can use carb cleaner for end of valve, as for the 02 sensors, you have to find out which ones are bad first. or replace all thats up[ to you. you have to get a 02 sensor socket for 3/8 drive. then they just turn out. the best way to get them out is have the car warm.

Change plugs, and Mass Air Flow sensor. This should do the trick

The P0420 code is a Catalytic converter efficiency code check the compression.Swap the #1 injector to a different location to see if the code follows.Test the coilpak. A cracked exhaust manifold is the most likely cause p0171 and 0174 Induction air leaks, vacuum or some kind fuel restriction, weak fuel pump, restricted fuel filter etc.You also could have an exhaust leak near the upstream o2 sensor. If youtake it in they will probably use smoke to find out where the leak is.

just tune up ur car periodicly, clean filter. clean ur sparkplug.