Please help with check engine light on my 97 corolla.

[kevmac]

I got the P0401 code which is "exhaust gas recirculation flow insufficient detected"

I understand that the EGR might be dirty or the vsv might be the problem.

Here is a picture of my egr with and without the cap and filter:




questions:
1. how do you clean the egr?
2. how do you check the vsv?

thanks.

[96TC]

How did you go about taking the cover off?

[tashirosgt]

The picture shows the top removed from the "EGR Vacuum regulator", not the EGR valve. This regulator can cause a EGR related code. My experience with it on my 1990 Prizm:
http://www.corolland.com/forums/inde...opic=19283&hl=

I'll look in the service manual and see what it says about the EGR valve and VSV when I get home.

[tashirosgt]

These are notes from the 1996 Prizm manual.
The EGR "Pressure Transducer" or "Vacuum Regulator"
Clean the filter by blowing compressed air through it and install it with the coarser side facing outward (I suppose "outward" = "upward")

The red thing at the left of your top picture is called the "Vacuum Regulator Solenoid" in the manual. The resistance across its terminals should be 37 to 44 Ohms. With the power to the solenoid disconnected, look where the pair of hoses enters the solenoid. Remove the hose of the pair that is nearest the electrical connector. Blow air into this nipple and see that it comes out of the contraption on the other side of the electrical connector.