EGR: cause of bad idle and high HC at idle?

[lotzagoodstuff]

So I removed and cleaned my EGR, reinstalled it, reset my TPS and IAC sensors, but my car still idles worse than I believe it should. I decarboned the intake (Seafoam via vacuum line) but I am still wondering about my EGR.

Although I swore it held vacuum when I tested it, my car idles better when I unplug the vacuum line to it. When I manually push the EGR in at idle it does hesitate, so I know it's operating. Lastly, I pulled the vacuum line off the EGR and plugged it and drove it around and idle quality and driveability seem to be better.

I believe the EGR is slightly opened at idle and causing my poor idle and high HC at idle exhaust readings.

Can anybody more experienced please verify/confirm.

Thank you

R. J.

 

[gunslinger]

You shouldn't have vacuum at the EGR at idle. If you do, there's a problem with the EGR solenoid or its circuit.

If the EGR is cracked open at idle, it will cause high HC and a rough idle.

 

[lotzagoodstuff]

Thanks, that makes sense. I pulled the solenoid off and it doesn't seem to "check" air in either direction, which tells me it's probably bad. I am going to try to clean it, I assume that this should be pretty easy to troubleshoot as I think it should be controlling vacuum going to the EGR.

Thanks again.