Diagnostic code p0171

https://www.yourmechanic.com/article/p0171-obd-ii-trouble-code-system-too-lean-bank-1-by-andrew-quinnhttp://p1719.enginecodes.net/

https://www.yourmechanic.com/article/p0174-obd-ii-trouble-code-system-too-lean-bank-2-by-blake-griffin
You may need to have it repaired. YOu mat have bad O2 sensors, a dirty air filter will cause a problem.

code P0171 is ; system too lean (bank1)
code P0174 is . system too lean (bank 2)

There are two common things that cause this code. The first is a dirty MAF sensor. The sensor is located on the side of the air filter cover. It can be removed and visually checked for dirt/debris. If it is dirty it can be cleaned with MAF sensor cleaner. The second is leaking intake manifold gaskets. The engine will need to be cold and a smoker will be needed to check them. The good news is the parts are cheap and they can be done in less that an hour.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Lean report from right side bank #1 oxygen sensor

Replace both sides upstream sensors if over 100,000 miles

They slow down & set a mil lamp

Leave the rear monitors

P0171 AND P0174
P0171 - System Too Engine Cylinder Lean Bank 1http://engine-codes.com/p0171.htmlForum CodePossible causes- Intake air leaks
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection Tech notes Dirty air filter of faulty air flow sensor are common causes for the P0171 code of the problem.


P0174 FORD - Fuel Injection System Too Lean Bank 2http://engine-codes.com/p0174_ford.htmlForum CodePossible causes- Intake air leaks
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection Tech notes The codes is usually set when there is an intake leak after the air flow meter, before replacing any parts check for loose or broken hoses and intake gasket leak. On Ford some models dirty air filter, and dirty or faulty air flow sensor are the cause of the problem.

Could be a coolant sensor fault. If the sensor cannot detect the coolant temperature it cannot a) trigger the radiator fan to come on and b) cannot inform the ECU and so the ECU continues the fuel rich injection cycle that is used when the engine is cold and starting up and so the engine continues to idle fast during 'closed cycle'. Check the sensor connection and wiring. If all looks well probe the wires with a voltmeter (if it has 4 wires then the pairs that are diagonally opposed are usually part of the same sensor function). Measure the voltage when engine is cold and again when hot, there should be a difference. If not the sensor is fried and should be replaced. Have the DTCs read from the diagnostics, chances are that some of the codes P0115 -P0119 and P0125, P0126 are logged.

No i would go for the o2 sensors ,two are fitted one before the cat and one after ,use universal ones now the 4 wire ones are 40euros each but the 3 wire ones are 90 euros each, in the box is a wire conversion colour code chart but basicly the two wires the smae colour go together either way around and the other two look at the conversion chart

--BANK 1 = DTCs P0171 (lean) and P0172 (rich)

-Check intake air system for leaks, obstructions and damage.
-Check air cleaner element, air cleaner housing for blockage.
-Verify integrity of the PCV system.
-Check for vacuum leaks.

I would try cleaning the Mass Airflow Sensor first. A dirty Mass Airflow Sensor is a common problem for triggering PO 171 & 174 codes.

Good luck and keep me posted.

P0171 means the system is lean on cylinder bank number one, with just the one code you could replace the bank one upstream O2 sensor and that will most likely cure the problem.

transmision shifts are based on engine load imputs a 171 and 174 refer to a lean condition therefor the shift is being based on an assumed cold engine so yes it may be related