code PO172

[skatematt]

Has anyone had this problem?

Code PO172
Definition:
BB Fuel system too rich bank 1
Probable cause (from autozone)

BB1: - Fuel system concern
BB2: - Ignition system concern
BB3: - MAF snsor faulty
BB4: - H)@S/AF ratio sensor fault

I only have an AEM short ram intake and P2R tbs and gaskets

[Kakashi]

What happened prior to the CEL coming up?

Any adverse or abnormal weather conditions?

[skatematt]

My wife drove it. Lol.
No driving during bad weather.
I'm gonna check all connections, then prolly reset battery.

[Kakashi]

Sounds like a good plan, report findings.

[DavisLasVegas]

do you have a scanner with live data? check the grams/min and see if the numbers change really crazy from idle to light cruise and wot. you could also have a leaking injector.

[BLK_Si]

It can be either bad/wrong grade gas, fuel cap not on right, bad spark plugs, bad fuel pressure regulator, clogged fuel return line, sticking fuel injectors or a bad primary o2 sensor.

Best cost effective way to tackle this is check your gas cap and spark plugs. Fill up with 93 octane and put a bottle of fuel injector cleaner with it. Reset the CEL and see if it comes back.

If the CEL still comes on, move onto the fuel lines and fuel pressure regulator. Also check for vacuum leaks. Check the primary o2 sensor last cause you don't want to blow money on that and not fix the problem.

[ncsumark]

Try this. may be related to intake.
Notes

DTC P0171: Fuel System Too Lean

DTC P0172: Fuel System Too Rich

NOTE:


Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
If any of the DTCs listed below are indicated at the same time as DTC P0171 and/or P0172, troubleshoot those DTCs first, then recheck for P0171 and/or P0172.
P0101, P0102, P0103: Mass air flow (MAF) sensor
P0107, P0108, P1128, P1129: Manifold absolute pressure (MAP) sensor
P0133, P1172, P1157,P2195, P2238, P2252, P2A00:Air fuel ratio (A/F) sensor (Sensor 1)
P0134, P0135: Air fuel ratio (A/F) sensor (Sensor 1) heater
P0137, P0138, P0139, P2270, P2271: Secondary HO2S (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
P2646, P2647, P2648, P2649:VTEC system
P0443, P0496: EVAP canister purge valve



Check the fuel pressure. Is the fuel pressure OK? YES - Go to step 2. NO
If the pressure is too high, replace the fuel pressure regulator, then go to step 7.
If the pressure is too low, check the fuel pump, the fuel feed pipe and the fuel filter. If they are OK, replace the fuel pressure regulator, then go to step 7.
Check for vacuum leaks at these parts:
PCV valve
PCV hose
EVAP canister purge valve
Throttle body
Intake manifold
Brake booster
Brake booster hose
Air Intake duct
Are the parts OK?

YES - Go to step 3.

NO - Repair or replace parts with leaks, then go to step 7.



Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.
Check for these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158 °F(70 °C)
Transmission in neutral
All electrical loads off
Monitor the ENGINE SPEED in the DATA LIST with the HDS, and hold the engine speed at 2,500 rpm . Once the engine speed is met, hold the accelerator pedal steady for more than 10 seconds . Did the engine speed vary more than 100 rpm from 2,500 rpm ? YES - Repeat step 5. NO - Go to step 6.
While holding the engine speed at 4,500 rpm , check the MAF SENSOR in the DATA LIST with the HDS. Is there about 5.7-8.3 gm/s ? YES - Check the engine valve clearances and adjust if necessary. If the valve clearances are OK, replace the injectors, then go to step 7. NO - Replace the MAF sensor/IAT sensor, then go to step 7.
Turn the ignition switch ON (II).
Reset the ECM with the HDS.
Do the ECM idle learn procedure.
Start the engine. Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.
Test-drive under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
Transmission in neutral
All electrical loads off
NOTE: DTC P0171 and/or P0172 may take up to 80 minutes of test driving to set. Using the HDS, monitor the air fuel feed back average (AF FB AVE). If the air fuel feed back average stays within 0.80-1.25, there is no problem at this time.



Check for Temporary DTCs or DTCs with the HDS. Is DTC P0171 or P0172 indicated? YES - Go to step 1. NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

[skatematt]

Well, I just got back on r&r and drove my car with the check engine light on. After a couple miles it went away and hasn't come back. So, I'm thinking it was just bad gas because it's been sittin a while.