Cleaning the Mass Air Flow Sensor

Hope this post will help, a lot of comments 2 pages. For the most part seems they found various vacuum leaks.
https://www.explorerforum.com/forums/index.php?threads/check-engine-light-p0171-p0174.148021/

If it is running lean, I'd check correct fuel pressure. Then check for a vacuum leak. 02 sensors are part of a tune-up. I don't like to replace parts unless I'm sure.

I can't rule out a maf sensor.

I found a YouTube video, MAF Sensor Cleaning in Slow Motion-rzrDIRZ-ccs.webm, that showed me how to remove the mass air flow sensor and spray clean it with CRC mass air flow sensor cleanser. I bought the kit (single use of Mass Air Flow Sensor Cleaner and Throttle Body and Air-Intake Cleaner at Walmart for $7.99 in store price) and cleaned the mass air flow sensor. Then I reset the check engine light by removing and replacing the negative battery terminal. It worked. The check engine light has stayed off. I have a 2005 Toyota Matrix.

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.

check for vacuum leaks or a faulty mass air flow sensor. all the codes have to do with engine too lean(too much air).

The mass air flow sensor for this ford freestar is located in the leftside of engine next to battery , in slides into air inlet tubing, i have enclosed a few pictures and a diagram to help you locate it, you will only see the back side of it where the connector goes until you remove it as in sits inside the air tube,hope this is helpful.

p0171 is lean exhaust bank one ( passenger side) and p0174 is lean exhaust bank 2 ( drivers side). First we need to look for vacuum leaks, low fuel pressure, Intake air leaks after the mass air flow sensor, pvc system. Because you have both sides lean I would start looking at these spots.

P0171 indicates a lean condition. The most common cause of this is a defective mass air flow sensor. Also check if any vacuum leaks.Replace MAf sensor,if cleaning the MAF does not help.
Thanks.

There is no p01001, it's either p0100, or p0101.
Anyway, it's the mass air flow sensor that's bad. The p0171 and p0174 is a lean condition on bank 1 and bank 2, which are the oxygen sensors. Change the mass air flow sensor and that should take care of the p0171 and 74 codes.
The mass air flow sensor can cause the 02 sensors to read lean.
The u1301, is a class 2 circuit short to battery. That, you have to test wires to find with a voltmeter/continuity tester.
I would try and find that short before changing the flow sensor, you don't need the new one shorting out, they are not that cheap.

--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.