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john -aka eauto
john -aka eauto, The Car Guy
Category: Saturn
Satisfied Customers: 16007
Experience:  ase tech 15 + years foreign domestic & european
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2001 saturn: mounted..the A/C compressor) was..pipe..exhaust manifold

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I have a 2001 Saturn SL1 that is setting a P0410 code. The AIR management valve (mounted just above the A/C compressor) was bad so I replaced it. I also found the pipe going into the exhaust manifold to be plugged with carbon. After cleaning the pipe out and replacing the valve the problem no longer occurs every time but still does happen. Could the ports in the exhaust manifold being partly clogged be the problem and if so what is involved in cleaning them?
Hi . Thank you for asking your question on JustAnswer. did you replace the egr valve

Thank you again for trusting us with your problem. John aka eauto
Customer: replied 6 years ago.
No the code is for the AIR system, not the EGR system.
my mistake...i thought i read po401 it the air pump powering on?
Customer: replied 6 years ago.
The pump does power on and has good flow through the combination valve but I can hear a difference in the pump when everything is connected v/s when I have the line off at the valve. The pipe thet runs from the combination valve to the exhaust manifold was clogged and I thought that the manifold ports themselves might have build up in them. I blew compressed air through the port in the manifold and it did seem somewhat restricted but I saw no way of cleaning the ports.
does it have good converter flow?
Customer: replied 6 years ago.

I beleave so, the car runs fine it just sets this code and wont pass emissions.

its usually th pump or the converter,

here is the test chart

The AIR system is used to accelerate the heating process of the catalytic converters by introducing outside air into the exhaust manifold. The air pump operates on cold engine starts when the catalytic converters work least efficient. The AIR system consists of the air pump, combination valve, air pipe/hoses, check valve, air pump solenoid, air pump relay and PCM. The PCM controls the ground for the air pump relay coil, which turns the air pump On and Off. The PCM also controls the ground for the air pump solenoid, which allows manifold vacuum to move the combination valve. The air pump solenoid and air pump relay are controlled independently to prevent exhaust gas from entering the air pump. During air pump operation, the Oxygen Sensor 1 (O2S-1) should read lean indicating the air pump system is working. DTC P0410 sets when the PCM commands the AIR system On and the O2S-1 signal does not indicate a lean condition for a certain length of time.

DTC P0410 will set if AIR system is being commanded On during a cold start and O2S-1 signal does not indicate a lean condition (voltage greater than 300 mV ) for a minimum of 2.5 seconds out of a 10 second test when:

  • Following parameters must be met for at least 6 seconds while the test is running
  • Engine speed is less than 3200 rpm
  • Startup ECT is between and 79°C (39° and 174°F )
  • O2S-1 above 600 mV for at least 2 seconds
  • IAT is greater than 0°C (32°F)
  • MAP is greater than 20 kPa
  • Ignition voltage is between 11 and 18 volts
  • Traction control is not active
  • Commanded air/fuel ratio is between 12 and 14 to 1
  • Calculated air flow is between 8 and 19 gm/s
  • No 5 volt reference, ECT, EGR, fuel trim, IAC, IAT, MAP, misfire, O2S-1 or TP sensor DTCs have been set. (Vehicles built after June 2000 only) If the air pump does not run long enough to obtain accurate test results, the PCM may run up to five independent tests if a test fails or does not fully run. The PCM must see the O2S-1 voltage go below 300 mV for at least 1.5 seconds out of a maximum 6 second test. The PCM will wait 20 seconds between each test if another test is going to run.

Conditions to run the active test:

  • ECT is greater than 75°C (167°F)
  • Commanded air/fuel ratio is 14.7 to 1
  • Engine is at idle for at least 4 seconds
  • STFT is between 122 and 134

DTC P0410 is a type B DTC.



  • If DTC P0413, P0414, P0418 or P1418 (air pump solenoid or air pump relay DTC) is set, diagnose that DTC first. That DTC is most likely the cause of the AIR system not working and should be diagnosed first.
  • Vehicles built after June 2000 are equipped with an internal air pump thermal switch. The switch may open as long as five minutes if the air pump becomes too hot. Wait at least 5 minutes with the ignition Off before running the AIR PUMP SERVICE BAY TEST.

To locate an intermittent problem, use Scan tool to run the AIR PUMP SERVICE BAY TEST. The engine should be at idle, and loop status should be closed. The PCM will run DTC P0410 when all DTC parameters have been met. The test will run for 30 seconds and DTC P0410 will fail if a fault occurred.

Refer to General Description-Systems for a further AIR system description.

Air pump resistance : 0.5-10 ohms graphicgraphic



john -aka eauto and 2 other Saturn Specialists are ready to help you
Customer: replied 6 years ago.
I had already gone through the chart and at that time the vehicle passed the test. I attempted to clean the port into the exhaust and do have at least some flow. It passed the test again the first time but then after driving for about 30 min., it failed the test and set a code keeping it from passing emissions again.
did you try replace the pump?
Customer: replied 6 years ago.
I have not but I think that may be the problem, however it passed emmissions so it will be ok till next year. Thanks for your help.