2003 Mazda 6 Codes po171 and po174

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)

could it be a clogged fuel filter
and how much does each of those cost to repair

fuel pump prob. 300

MAF sensor 90

but what about the others

thanks

You need to check every one of them out.

well I cleaned the MAF sensor my self not much of a change

checked for leaks with carb cleaner didnt find anything


there seems to be no significant loss in power

and i may be idling slightly rougher then it use to


can you help me narrow it down from there

i am experiencing the same issue with my 2003 mazda and curious if you ever find the root cause of eng code 171 & 174?

thanks