01 Silverado Emissions P0420, P1416 & P0753 Codes

Discussion in 'Chevy Truck Forum' started by designbuildguy, Sep 12, 2009.

  1. designbuildguy

    designbuildguy New Member

    Sep 12, 2009
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    Team Leadership / MonaVie
    Central Coast, California
    Hey there, new to the site hoping someone can help. I have a 2001 1500 Silverado 4.8L Z71 with 191k miles on it. Been and still is an AWESOME truck. About 6 months ago the check engine light came on and I had a buddy read my code - P0420. I ran it for the last 6 months with the light on (oops). Long story short I ended up buying a tester (FYI $100 from Wal-mart) and hooked it up this weekend and it came back with 4 codes and I’m not sure what I need to do to fix them.

    First code was P0420 Catalyst System Efficiency below Threshold Bank 1 (one P0420 was a freeze frame, the other didn’t indicate it was FF or not – what is a freeze frame?),

    the 3rd was P1416 – Air System Bank 2,

    the 4th was P0753 Shift Solenoid A - Electrical. About the shift solenoid I haven’t felt anything strange in the shifting at all – is this about the transmission?

    About the others – is this the O2 sensor? As far as exhaust systems – I just know some of the buzz terms but I’m a real rookie with the cats and sensors and smog etc…

    Is there a service manual that tells me what I need to do to trouble shoot each of these issues? Or do I need to replace some O2 sensors (I hear there are front and backs) or a Cat or ??? One code told me Bank 1 and the other told me Bank 2 (is bank 1 vehicle right or left?)

    After I wrote the codes and descriptions down I used the reader to erase the codes and turn off the light, hoping to see something pop up to attack that problems in the order they appear, but I’ve driven it for about 30 miles so far and nothing has come back up yet, but I figure I better get things working right, I need to keep this truck around for a while still.

    Thanks for the help, greatly appreciated.

  2. huntintruck95

    huntintruck95 Full Member

    Sep 10, 2009
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    Sounds like your cats might be getting plugged,when i worked at the dealership the we would replace the y pipe and both the cats come with it but it is exspensive i would go down to the exhaust shop and have them tested. and you probably just should replace the O2s they need replaced after so many miles the heater in them will quit workin.
  3. mudseeker

    mudseeker Senior Member

    Feb 2, 2006
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    fixer of many things
    freeze frame is just that, it takes a "picture" of all the sensor data at the moment the code was set to help solve the problem.
    the air pump code is the cause for the cat code, so start there. could be as simple as a loose hose(happened to my sisters trailblazer).
    corn stalk was the culprit in her case
    A Secondary Air Injection (AIR) pump is used on this vehicle to lower tail pipe emissions on start-up. The Powertrain Control Module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump and the AIR solenoid valve. Engine vacuum is applied to the AIR shut-off valve when the AIR solenoid is energized. The engine vacuum opens the AIR shut-off valve which allows air to flow to the exhaust manifolds.

    The PCM monitors the Heated Oxygen Sensor (HO2S) voltages to diagnose the AIR system.

    During the AIR test, the PCM activates the AIR pump during Closed Loop operation. When the AIR system is activated, the PCM monitors the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.

    If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, the Diagnostic Trouble Code (DTC) P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 or P1416 to indicate on which bank the AIR system is inoperative.


    • DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0161, P0170, P0171, P0172, P0173, P0174, P0175, P0200, P0300, P0335, P0336, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P0440, P0442, P0446, P0506, P0507, P1133, P1134, or P1258 are not set.
    • The startup Engine Coolant Temperature (ECT) is less than 70°C (158°F) .
    • The engine run time is more than 2 seconds .
    • The Manifold Absolute Pressure (MAP) sensor is more than 75 kPa .
    • The engine load is less than 40 percent .
    • The engine air flow is less than 20 grams per second .
    • Engine speed is more than 900 RPM .
    • The vehicle speed is more than 15 km/h (25 mph) .
    • The ignition voltage is more than 11.7 volts .
    • The air fuel ratio is 13.125:1.
    • The ECT is between 70-110°C (158-230°F) .
    • The Intake Air Temperature (IAT) is more than 2-100°C (36-212°F) .
    • The fuel system is not operating in power enrichment or Deceleration Fuel Cut-off (DFCO) .
    • The short term fuel trim is in cells 5 or 6.

    • The HO2S voltage does not go below 222 mV for 1.2 seconds or more.
    • Short term fuel trim does not go above a predetermined amount.


    • The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Use a scan tool in order to clear the MIL and the DTC.

    IMPORTANT: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

    • Casting flash in the exhaust manifold may restrict the amount of air flow necessary to affect the HO2S voltage. If you suspect this, remove the air pipe from the manifold and inspect the passage.
    • Using the Freeze Frame/Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature etc. that you observed. This will isolate when the DTC failed.
    • For an intermittent condition, refer to Symptoms - Computers and Control Systems. See: Symptom Related Diagnostic Procedures

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