98 Lumina LS Code 1401

[timheis]

I am getting a 0401 code. The car runs good but I cannot find out what the 0401 means. Has anyone had this code before? What was the fix?

Thanks
Tim

[jeffcoslacker]

P1401 Heated Catalyst Current too High During Heating (Bank 1) (BMW) P1401 DPFE Sensor High Voltage (Ford, Mazda) P1401 EGR Temperature Sensor (Infiniti)

I don't see 1401 as a valid GM code, but this info might not be complete...

[timheis]

Originally Posted by jeffcoslacker

P1401 Heated Catalyst Current too High During Heating (Bank 1) (BMW) P1401 DPFE Sensor High Voltage (Ford, Mazda) P1401 EGR Temperature Sensor (Infiniti)

I don't see 1401 as a valid GM code, but this info might not be complete...

This was a typo

The code is 0401

[jeffcoslacker]

Originally Posted by timheis

This was a typo

The code is 0401

P0401 Exhaust Gas Recirculation Flow Insufficient Detected


Might need to clean the passage or replace the EGR valve...

[jeffcoslacker]

Originally Posted by jeffcoslacker

P0401 Exhaust Gas Recirculation Flow Insufficient Detected


Might need to clean the passage or replace the EGR valve...

I'm thinking a clogged passage might be what you want to look at first, that EGR is position sensing, so it should be setting a code for EGR position if the EGR itself were going bad....

[timheis]

Does cleaning the passage entail removing the valve? Is this an easy job? I am not a mechanic but I can do some easy stuff.

[jeffcoslacker]

Originally Posted by timheis

Does cleaning the passage entail removing the valve? Is this an easy job? I am not a mechanic but I can do some easy stuff.

Yes, pretty straightforward, remove, clean the passage best you can, try to keep the crud from going into it (I run a shop vac hose right bext to it as I clean to inhale the loose crud), careful not to scratch the metal (don't use hard metal scraper or anything), make sure the gasket seal is good and there is nothing that would prevent the valve from seating as you put it back together....

[richtazz]

If your car is a 3800, check the two o-rings and the spring in the PCV valve housing (it's located on the passenger side end of the upper intake plenum). The MAP sensor is located in the top of this housing, and the PCM uses MAP sensor vacuum signal to test EGR flow. If one or both of these o-rings is missing or damaged, or if the spring is missing allowing the PCV valve to come off it's seat, it will trip a P0401 code, even though no actual EGR problem exists.

[timheis]

ritchazz, I do not know what a 3800 is. I know I have a 3.1L in it. Would I use the same proceedure?

Tim

[maxwedge]

Originally Posted by timheis

ritchazz, I do not know what a 3800 is. I know I have a 3.1L in it. Would I use the same proceedure?

Tim

Tim different set up on the 3100, continue with the normal egr diagnostics.

[richtazz]

The 3800 is an optional engine in the 98 Lumina. Since yours is a 3.1, then my suggestion doesn't apply here.

[BNaylor]

I noticed the thread title stated this was a '98 Lumina LS.

Just to clarify the '98 Lumina LS only had a 3100 and there was no 3800 engine option. However, the LTZ model had both the 3100 and 3800 available. FYI.

[richtazz]

Although the MAP sensor is located in a different location on the 3.1, an insufficient vacuum signal to the MAP (due to a cracked/disconnected vacuum hose) will still trip a P0401 code. If cleaning the EGR valve and passages doesn't help, check the vacuum lines running to the MAP and PCV, as they are fed off the same intake port.

[BNaylor]

Originally Posted by richtazz

Although the MAP sensor is located in a different location on the 3.1, an insufficient vacuum signal to the MAP (due to a cracked/disconnected vacuum hose) will still trip a P0401 code. If cleaning the EGR valve and passages doesn't help, check the vacuum lines running to the MAP and PCV, as they are fed off the same intake port.

I've never heard of that on a 3100 cause an EGR flow problem. On a 3100 the MAP sensor has about a one inch vacuum line where it mounts to the backside of the UIM so unless that is damaged or removed I doubt it. The PCV valve gets its vacuum source right off the throttle body and shares the source with the purge solenoid. He would probably have more than just a EGR P0401 DTC and other issues.

I would agree that removing and cleaning the EGR valve and the manifold/exhaust passages is the first and proper step to troubleshooting the problem.

BTW - After cleaning EGR the DTC must be reset with a scanner to see if that did any good. Otherwise it will take quite a few drive cycles to clear.