EGR Excessive flow - Cleaned upper intake, now what?

[MoonieGT]

CEL came on last week --> EGR excessive flow. So I pulled the upper intake and cleaned it out. WOW was it dirty. Got it all cleaned up. Drove around for 100 miles and no CEL . Thought I was in the clear but at a mile 104.9... . CEL is back.

What is the next course of action? Is it possible that I didn't do a good enough job? The manifold went from black to silver and I verified flow through the EGR hole by blowing air through it...

[goofygrin]

excessive flow means the flapper/plunger is likely gummed open. Did you clean it? (ETA url: http://forum.miata.net/vb/showthread.php?t=367546)

Also you can reroute the EGR line: http://www.miata.net/garage/egr0902.html

[MoonieGT]

Thanks for those links. I didn't actually clean the EGR valve, doh! The guide I read was about cleaning the intake manifold, makes sense that I should have cleaned the EGR valve too...

Question about the reroute: I think I read that you shouldn't reroute the EGR because it reduces emissions by 70% at part throttle and is not active under full load (i.e., it doesn't rob you of performance).

[goofygrin]

I did not reroute mine and after a super thorough cleaning I've not had it return (~3k miles). I'd prefer to not reroute it since it was designed to run the way it does. I don't particularly care about emissions honestly, so if it comes down to me rerouting in the future I will.

[MoonieGT]

I'll give cleaning it a try first. I don't have take the upper manifold off again to pull the valve do I?