PO 171 & 174 (Running too lean)


Andra
06-09-2004, 09:24 PM
Can someone tell me how to fix this code? OBD II says code 171 running too lean bank 1 and code 174 running too lean bank 2. Is this a simple adjustment or do I need a diagnostic machine to adjust the air/fuel ratio? Would a tune up help?

Any advice is appreciated.

cobradude360
06-11-2004, 07:14 AM
yes i would say it would help cuz more then likely ur plugs are fouled

ghost1977
08-22-2006, 05:52 PM
Can someone tell me how to fix this code? OBD II says code 171 running too lean bank 1 and code 174 running too lean bank 2. Is this a simple adjustment or do I need a diagnostic machine to adjust the air/fuel ratio? Would a tune up help?

Any advice is appreciated.


fuel filter

2OOOLS
08-23-2006, 11:41 AM
Can someone tell me how to fix this code? OBD II says code 171 running too lean bank 1 and code 174 running too lean bank 2. Is this a simple adjustment or do I need a diagnostic machine to adjust the air/fuel ratio? Would a tune up help?

Any advice is appreciated.


Fuel System DTC Reference list:

--BANK 1 = DTCs P0171 (lean) and P0172 (rich)
--BANK 2 = DTCs P0174 (lean) and P0175 (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.

Are any of the above concerns present?

2OOOLS

PS.Also see the following:

http://www.cyberforma.com/tutorials/auto/dtc/001.gif

hope this will help,
2OOOLS

JianJeff
10-04-2006, 10:25 PM
You need to replace the Mass Airflow Sensor. The MAS is located on the air intake tube between the air filter canister and the engine. I would also highly recommend replacing the O2 sensor too. The O2 sendor is located in the exhaust pipe so change it when the engine is cool.

Once yo have replace the MAS then you need to disconnect the battery for 5 - 10 minutes to allow the codes to be erased... unless yo uhave a code reader to erase them.

reekor
10-06-2006, 12:03 AM
I wouldn't jump into replacing the Mass Airflow Sensor. before I tried to clean it first. But yes this is a common problem for triggering PO 171 & 174 codes.

You need to replace the Mass Airflow Sensor. The MAS is located on the air intake tube between the air filter canister and the engine. I would also highly recommend replacing the O2 sensor too. The O2 sendor is located in the exhaust pipe so change it when the engine is cool.

Once yo have replace the MAS then you need to disconnect the battery for 5 - 10 minutes to allow the codes to be erased... unless yo uhave a code reader to erase them.

mrl1214
01-27-2013, 10:02 AM
i have repalced all o2 sensors and MAS sensor, but still receive the 171 and 174 errors. Any ideas? Intake gasket also replaced due to a bulletin that was released regarding the torque on the manifold sometimes needing to be done.

flip1daddy
02-01-2013, 12:37 PM
Change the fuel filter. Check the fuel pressure with a (fuel) pressure gauge at the schraeder valve on you fuel rail. If the pressure is good then look toward replacing the fuel injectors.

flip1daddy
02-01-2013, 12:52 PM
Check this
http://www.justanswer.com/ford/1aigz-fix-obd-ii-codes-171-174.html

way2old
02-01-2013, 06:13 PM
What year vehicle are we working on? Different model years have common failure points. Some have a PCV line that will suck a hole in it causing a lean condition.

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