Service Engine Code PO404

[mikeso_81]

Hi,

I have a 2001 Pontiac grand Prix GT 3.8L non supercharged and the Service Engine light keeps popping on and off. It is on one day and then off the next. For example, it came on today and turned off after I turned the car on and off 3 times while going to various stores. When the light is on the accelerator bogs a little when the gas is pressed after making a complete stop. Anyhow, the code that is coming up is PO404. Could this be the EGR Valve? The printout I received from AutoZone states 5 different things. Another probable cause listed is a Failed EGR Position sensor.

Thanks

[tblake]

P0404 = EGR Valve open position performance.

http://www.automotiveforums.com/vbul....php?t=1052953

You could remove the EGR, clean, make sure the pintle moves freely, replace the gasket and then reinstall it. There is no "EGR position sensor" on this car. The PCM monitors the MAP sensor data (if I'm not mistaken) to verify the EGR is functioning correctly. Make sure the vacuum line going to the MAP, and all your vacuum lines are in good shape. You might also want to replace your PCV valve if you have not in a while.

[tblake]

Take that back, there is not vacuum line going to the MAP sensor on this motor. But remove the MAP sensor itself and check its rubber seal.

[mikeso_81]

What should I clean the EGR with? Carb cleaner? If this does not work, should I end up buying a new EGR valve?

Thx

[tblake]

Yes carb cleaner is OK to use on the EGR valve. Just try and not get a lot up inside, ie spray the pintle as the EGR is upside down, or the carb cleaner could damage the stepper motor windings inside.

Also make sure the EGR bore is clear of carbon.