I have a 05 RSX-S and its throwing the following code P0171. Acura told me to leave the car overnight and they'd add some engine cleaner. That didn't do anything. Came back on 20 miles later. Please help so I don't get ripped off. Thanks

I know it's reffering to running lean.

 

maybe you have a vacuum leak somewhere

 

after a quick google search since I can't remember my dealer number to sign into the honda network, p0171 can be caused by vacuum leaks as stated by slomo civic. Here is the info I found from just typing in "P0171 Acura" http://repairpal.com/OBD-II-Code-P0171-and-P0174

 

What kind of mileage is on the car? First step in the flow chart is to check valve clearance.

 

114K+ and no mods.

 

I would do a valve adjustment. I know on the MDX we have had alot of issues with valves tightening up over time.

Let me know if that works I'm curious now?

 

There is a bulletin on this from Honda.

SYMPTOM
The MIL comes on with one of these DTCs:
• P0134 (air fuel ratio [A/F] sensor [sensor 1] heater
system malfunction)
• P0135 (air fuel ratio [A/F] sensor [sensor 1] heater
circuit malfunction)
• P0171 (fuel system too lean)
• P1157 (air fuel ratio [A/F] sensor [sensor 1] AFS
circuit high voltage)
PROBABLE CAUSE
Under-hood temperature causes grease from an
under-hood fuse box connector to melt, travel down
through the engine wire harness, and drip onto the A/F
sensor 4P connector.

 

CORRECTIVE ACTION
Replace the A/F sensor, and install a subharness kit.
PARTS INFORMATION
A/F Sensor:
P/N 36531-RRA-013
Subharness Kit (includes subharness and wire ties):
P/N 06320-SNA-315

 

Here is a flow chart too.
Check the fuel pressure.


Is the fuel pressure OK? YES - Go to step 2.

NO - Check these items:

If the pressure is too high, replace the fuel pressure regulator.■

If the pressure is too low, check the fuel pump, the fuel feed line, and the fuel filter, and replace the fuel pressure regulator.■


Start the engine. Hold the engine at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on.

With the D17A1 or D17A2 engine, check the primary HO2S (Sensor 1) output with the HDS or a scan tool. With the D17A6 engine, go to step 4.


Is the output less than 0.3 V or more than 0.6 V? YES - Replace the primary HO2S (Sensor 1).■

NO - Go to step 4.


Turn the ignition switch OFF.

With a vacuum pump/gauge, 0-30 in.Hg, apply vacuum to the evaporative emissions (EVAP) canister purge valve (A) from the intake manifold side.


Does the valve hold vacuum? YES - Check the engine valve clearances and adjust if necessary (P0172 only). If the valve clearances are OK, replace the injectors.■

NO - Replace the EVAP canister purge valve.■