P0401 and P0402 2000 Ford Taurus

The check engine light on my 2000 Ford Taurus 24 Valve DOHC V6 came on and after scanning with an OBD2 Scan Tool, I received an P0402 (excessive EGR flow). I replaced the DPFE sensor and , since the car was 'missing', I also replaced the spark plugs (the car has 40K miles). This fixed the problem but after a week, I received a P0401 (low EGR flow) code and the 'missing' is back.

Replacing the back spark plugs required removal of the intake manifold. When reinstalling the manifold, I seated it as best I could and I noticed a slight gap all around the entire mainfold and the top of the engine after installing the bolts. I do not know if this is 'normal' and if it is not, I am concerned that this might be causing the P0402.

Is anyone familiar with this problem or have any advice??

Thanks in advance

Did you replace any of the gaskets or o-rings that may have been removed? I do not reuse o-rings or gaskets due to the fact that they have a higher tendancy to fail when you reuse them. Did you replace the plug wires at the same time? After replacing the spark plugs and clearing codes, what code did you get when the check engine light came back on?

I just had the same problem (EGR insufficient and EGR excessive) and I must say the I am not a certified mechanic I am a part changer. I replaced the EGR valve and the 4 oxygen sensors (if you do this use Ford sensors). This didn't fix the problem, I then changed the Vacuum Regulator Solenoid and a tube mounted sensor part numbers F63Z-9J459-AA, and 4U7Z-9J460-AA. this fixed my check engine light and code issues, as well as it stopped idling so high that it caused the trans to jump into gear. It sometimes jumped so hard that I thought I had a broken motor mount. Good Luck with this...

HI ¡

Start by checking your EGR valve, It is in good conditon ? if it is bad it will not close or open the way it should do. Replace your EGR valve if you suspect of bad-malfunction.... Also check the vacuum line that enters on the top of the EGR valve (the one that comes from the EGR solenoid) check if it is not clugged or broken......

read the post! his is fixed! He's not here looking for advice he's explaining what fixed his. plus look at the dates of the post! Do you think it's still relevant to the original thread starter!