Hello I'm newbie here. I need help here is my issue with 2011 Prius. The car has 245K miles and run very well with engine light on and I cannot smog until the issue is fix. The code is P0171 B1 running lean or rich. Here's what I have done so far: 1. Replaced MAF, not help at all. 2 Replaced O2 upstream sensor and the code went away but code P2195 comes on. 2. So I return the O2 sensor and buy another expensive O2 sensor. 3. Install the new O2 sensor and now I'm getting code P0171 back along with other code P219A and P3190. Now I'm stuck with code P0171, P219A and P3190 and I need get the smog check. I am order a new MAF sensor and see if that can help. I don't think is my fuel pump, PLEASE Help. Thank you in advance. nphra
Here is my current ODB readings fuel sys 1 CL fuel sys 2 NA calc load % 95.7 ECT (*F) 196 STFT B1 (%) 1.6 LTFT B1 (%) 28.1 MAP (inHg) 26.6 Eng RPM 2022 Veh speed (mph 68 Spark Adv (*) 21.5 IAT (*F) 86 MAF (lb/min) 2.3 TPS (%) 29.8 O2S B1 S2 (V) 0.76 STFT B1 S2 (%) 99.2 Run Time (sec) 215 Lambda B1 S1 0.987 O2S B1 S1 (V) 3.174 Command EGR (%) 49.4 Command EVAP (%) 24.7 Warm up DTC Clr 5 Clr Dist (miles) 20 BARO (InHg) 14.1 Lambda B1 S1 0.987 O2S B1 S1 (mA) -0.05 CAT Te 11 (*F) 1272 Cat Te 12 (*F) 1138 ECU Volts (V) 14.355 LOAD Value (%) 49 EQ Ratio 0.993 Rel TPS (%) 12.5 TPS B (%) 64.7 Command and TAC (%) 29.8 Clr Time 1h1m
What test have done that would lead you to think that the fuel pump is not the problem? Let's look at your data. Long term fuel trim is at +28% at highway cruise/accel- so the ECM is adding a bunch of fuel (aka, a lean condition). But short term trim is close to zero, indicating that right then, the ECM has good fuel control. The B1S1 air fuel sensor is just below 3.3V (slightly rich which matches the lambda figure and mA current). B1S2 is between 700 to 800mV- so I believe what the B1S1 is reporting. MAP shows 3-4" of vacuum when calculated load is over 90%, so I don't immediately distrust the MAF reading. Now an intake or exhaust restriction could result in the engine performance codes but by itself wouldn't cause a lean code. I would expect most cam timing faults to set some type of cam sensor code. So that pretty much leaves fuel delivery- such as low pressure and volume from the fuel pump or fuel injector problems. If your fuel pump can maintain pressure at spec under all operating conditions and meet or exceed volume requirements then you won't think or believe that it's good- you will KNOW that it's good. Posted via the PriusChat mobile app.
Thank you for your help, you explained very well. I assumed fuel pump was good because It's not acting out, I have not way to confirmed it. The car drive smoothly even at high speed though. Changing out fuel pump will be my next step. I will order fuel pressure tester. By looking at my data, is it possible that I have vacuum leak ? Also I thought the standard range for LTFT is -10% - +10% or close to 0% ? Please help.
First off, do you have any misfires? If you have a code scanner that you can monitor misfire counts that would be essential. If you find that you do have a misfire on a particular cylinder, you’ll have to determine if it’s a bad coil. You can do this by swapping the coil with another cylinder that is showing no misfire. If you still have the misfire on the cylinder in question, you have eliminated the coil being the problem and the fuel injector becomes suspect. With the fuel injector being the problem this will cause an imbalance in the air fuel ratio and setting a P219A code.
Thank you for your replied everyone. Here is my new reading with Code P219A after changed Fuel pump, the long and short fuel trim a lot better, I think., not expert though. Name New Fuel Pump fuel sys 1 Cl fuel sys 2 NA calc load % 92.9 ECT (*F) 194 STFT B1 (%) -1.6 LTFT B1 (%) 10.2 MAP (inHg) 26 Eng RPM 2117 Veh speed (mph 38 Spark Adv (*) 21.5 IAT (*F) 115 MAF (lb/min) 2.4 TPS (%) 29 O2S B1 S2 (V) Down stream 0.8 STFT B1 S2 (%) 92.2 Run Time (sec) 202 Lambda B1 S1 0.986 O2S B1 S1 (V) Up stream 3.242 Command EGR (%) 50.2 Command EVAP (%) 5.9 Warm up DTC Clr 0 Clr Dist (miles) 5 BARO (InHg) 14.1 Lambda B1 S1 0.986 O2S B1 S1 (mA) -0.01 CAT Te 11 (*F) 1003 Cat Te 12 (*F) 641 ECU Volts (V) 14.023 LOAD Value (%) 48.2 EQ Ratio 0.993 Rel TPS (%) 12.9 TPS B (%) 63.5 Command and TAC (%) 29 Clr Time 0h24m
Is it possible that my O2 senor #2 (Down stream) is bad ? because on the live Data it show 000 and it slowly move. Please advise. Thank you
Ummm. No where in my previous post did I say "hey you should just replace the pump and see if that helps". If you want to throw parts at this car then why not replace the injectors? Might as well (could even help with the imbalance code). That said, ANYTHING that affects how a cylinder functions can trigger that code- compression, valve operation, exhaust manifold leak, fuel injector (or injector wiring), etc. If fuel trims went from high +20's % to +10% (under all conditions), then yes that's an improvement. No, the downstream oxygen sensor can't cause the imbalance code, and it sounds like normal sensor operation. Sometimes the sensor isn't "turned on" and will read near 0. When driving it is usually about 0.7 - .8V but it will slowly change , anywhere from 0 to 0.9V depending on how you drive. Good luck Posted via the PriusChat mobile app.
It's not hard, and with your miles? Here's a video, by @NutzAboutBolts: Attachment has torque values.
Great video but cleaning was rather cosmetic (because intake was not really in need of cleaning). These tiny passages were not brushed: If those clogged then HG goes. So they say. If actual intake channels have dirt so that rag gets dirty it is meaningless unless it’s a race car that need every ounce of power out Even with those beasts porting the manifold to head might be higher in priority
A good fuel injector cleaner and chasing down air leaks would be my next move. My car tripped the lean code and ltft was 20%. It was because I reused the intake manifold gasket when cleaning everything. New gasket solved the issue. Throwing parts at a high mileage car can be a huge rabbit hole. Chase any leaks properly first.
Thank you everyone for your replied . You all made a good point. I'd cleaned the injectors and code P219A come back on. I will clean the intake manifold and EGR this weekend.
