DTC P0171 and EGR Valve

[funtruck]

My car has been giving me the DTC codes P0171 and P0174 codes recently. I though it was something to do with the stall issue for the 03's. I've fixed that issue and it popped the codes again. I'm hearing a good vacuum leak from the back of the blower and today I heard it cycle on and off. So I isolated it to the EGR valve. Has anyone had any similar experiences? Thankfully the car still run's fine.

It's bone stock except for the K&N FIPK. I'm positive it's not a vacuum line loose behind the supercharger.

I just read in the service manual that the EGR valve/gasket leak will cause these codes.

I'm just wanting feedback from someone who's experienced this before.
Thanks

 

[ShelbyGuy]

Datalogging the DPFE sensor will tell you whether the EGR valve is opening or opening at the wrong time.

 

[Goodlife]

Yeah gross leak detected both banks.
Check that egr

 

[hotcobra03]

my very first vacuum leak was from the pcv hose right at the blower the black elbow was ripped underneath from rubbing on the one with the red hoses you will need to remove it to see the hole...i have bbk l/t and off road x and i constantly have these codes....i have been working on my car for a couple of weeks and have found that everytime i disconnect any hoses or electric connectors that the cel lite comes right on for that part po1409 is for egr system....i just had po 172 o2s slow responce...i almost have to clear the cel lite 4 times a week

 

[funtruck]

Thanks, I don't have a datalogger (yet). I just rented the AutoZone tool. I will definitely replace the EGR valve though.

 

[hotcobra03]

why buy the egr no need to




P0171 - System to Lean (Bank 1) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. Refer to Section 1 , Powertrain Control Software, Fuel Trim for more information. Air Measurement System
MAF sensor (contaminated, damaged, malfunctioning, etc.)
Fuel System
Fuel pressure regulator (leaking, malfunctioning, etc.).
Fuel filter plugged, dirty.
Fuel pump (weak, check valve leaking, etc.).
Leaking/contaminated fuel injectors.
Low fuel pressure or running out of fuel.
EVAP canister purge valve leaking (when canister is "clean").
Fuel supply line restricted.
Fuel rail pressure sensor (incorrect reading).
Air Induction System
Air leaks after the MAF.
Vacuum Leaks.
PCV system (leak, valve stuck open, etc.)
Improperly seated engine oil dipstick.
Exhaust System
Exhaust leaks before or near the HO2Ss (exhaust manifold gasket, mating gaskets, etc.)..
EGR System
EGR valve tube/gasket leak
EVR solenoid vacuum leak
Secondary Air Injection
Damaged/malfunctioning secondary air injection system (mechanically stuck valve).
View Freeze Frame Data to determine operating conditions when DTC was set. Observe LONGFT1 and 2 PID(s). Refer to Section 2 , Adaptive Fuel DTCs Diagnostic Techniques for more in
P0174 - System to Lean (Bank 2) The Adaptive Fuel Strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. Refer to Section 1 , Powertrain Control Software, Fuel Trim for more information. See Possible Causes for DTC P0171. See Diagnostic Aides for DTC P0171

 

[hotcobra03]

good luck egr valve going bad is like hitting the lottery




P1400 - DPF EGR Sensor Circuit Low Voltage Detected The EGR monitor checks the DPF EGR sensor signal to the PCM for low voltage. The test fails when the average voltage to the PCM drops to a voltage less than the minimum calibrated value. DPFEGR circuit short to GND
Damaged DPF EGR sensor
VREF short to GND
Damaged PCM
A DPF EGR PID reading less than 0.2 volt with the key ON and engine OFF or running, indicates a hard fault.
P1401 - DPF EGR Sensor Circuit High Voltage Detected The EGR monitor checks the DPF EGR sensor signal to the PCM for high voltage. The test fails when the average voltage to the PCM goes to a voltage greater than the maximum calibrated value. DPF EGR circuit open
VREF short to PWR
Damaged DPF EGR sensor
DPFEGR circuit short to PWR
SIG RTN circuit open
Damaged PCM
A DPF EGR PID reading greater than 4.5 volts with the key ON and engine OFF or running, indicates a hard fault.
P1405 - DPF EGR Sensor Upstream Hose Off or Plugged While driving, the EGR monitor commands the EGR valve closed and checks the differential pressure across the EGR orifice. The test fails when the signal from the DPF EGR sensor indicates EGR flow is in the negative direction. Upstream hose is disconnected
Upstream hose is plugged (ice)
Plugged or damaged EGR tube
Look for signs of water or icing in hose
Verify hose connection and routing (no excessive dips)
Verify DPF EGR sensor proper mounting and function (view DPF EGR PID while applying and releasing vacuum directly to sensor with a hand pump)

P1406 - DPF EGR Sensor Downstream Hose Off or Plugged While driving, the EGR monitor commands the EGR valve closed and checks the differential pressure across the EGR orifice. The test fails when the signal from the DPF EGR sensor continues to indicate EGR flow even after the EGR valve is commanded closed. Downstream hose is disconnected
Downstream hose is plugged (ice)
Plugged or damaged EGR tube
Look for signs of water or icing in hose
Verify connection and routing (no excessive dips)
Verify DPF EGR sensor proper mounting and function (view DPFEGR PID while applying and releasing vacuum directly to sensor with a hand pump)

P1408 - EGR Flow Out of Self-Test Range (Non MIL) This test is performed during the KOER on demand self-test only. The EGR system is commanded ON at a fixed engine speed. The test fails and the DTC is output when the measured EGR flow falls above or below the required calibration . For vacuum activated systems, see Possible Causes for DTC P0401. For electric motor system, see Possible Causes DTC P0400. For Electric EGR, use the output state control function of the scan tool and monitor the MAP PID (MAP) and the EEGR PID (EGRMDSD) while commanding the EEGR on. If EGR is introduced into the engine at idle, the rpm will drop or stall out. For vacuum systems see Diagnostic Aids for P0401.
P1409 - EGR Vacuum Regulator Solenoid Circuit Malfunction This test checks the electrical function of the EGRVR solenoid. The test fails when the EGRVR circuit voltage is either too high or too low when compared to the expected voltage range. The EGR system must be enabled for the test to be completed. EGRVR circuit open
VPWR open to EGRVR solenoid
EGRVR circuit short to VPWR or GND
Damaged EGRVR solenoid
Damaged PCM
The EGR vacuum regulator solenoid resistance is from 26 to 40 ohms