EGR Codes

[Fast4SHO]

I previously posted a thread with codes from my 91 Vulcan Taurus, but figured out that I have a 91 with the 3 digit code system. Here are the codes:

326 (R,M) Pressure Feedback EGR shows low pressure EGR not seating or not seating intermittantly - PFE

327 (O,R,M) EGR feedback signal is/was low - EVR or PFE


Maybe this is a dumb question, but what does the EGR do and how will its malfunction affect my car?

 

[HopefulSHO]

EGR (Exaust Gas Recirulation) let's a small bit of exaust gas into the intake manifold during crusing and part throttle (I don't think it's used during WOT or idle). This inert exaust gas lowers the combustion chamber temps; intern your NOx emissions are lessened. Most engines will run just fine with this system disabled; some will ping a bit under some load.

 

[Electricat]

To ad to what Hopeful said, EGR also helps the gas mileage a bit.

Also, if you are in one of the Ohio counties that requires emissions testing, EGR problems may cause you to fail the test.