95CUTLASSSUPREME

New To This Forum, I Am Hoping Someone Can Help. The Mil(service Engine Soon Light) Has Been Coming On Intermittently For The Last Month. Initially My Tech Was Unable To Download Any Codes. Changed Plugs, Wires, Fuel Filter And Pcv. My Tech Performed Fuel Induction Cleaning Service. The Light Came On And I Stopped At The Garage And My Tech Was Able To Dowload Code 77(digital Egr #3 Solenoid Error). I Changed The Egr And Am Still Having The Same Problem And Same Code. My Tech Suspects Some Kind Of Wiring Problem That Could Be Causing The Solenoid To Malfunction. Usually The Light Will Come On When I Am Braking From Highway Speed(45-50mph). It Then Goes Out About 5-10 Minutes Later. I Am Suspecting Some Kind Of Vacuum Problem But I Am Unsure At This Point. Sometimes It Is Ok For A Day Or Two. The Car Runs Great, Doesn't Seem To Cause Any Performance Issues. It Is The 3.1v6 With 76,000 Miles. Car Is In Otherwise Mint Condition, Looks New. Thank You In Advance For Any Suggestions.

Bill V

You have a partially plugged EGR port. Sometimes it can be cleaned out without removing the intake plenum. The method I use is to remove the valve and run a flexible cable (such as a speedo cable) through the port with a slow speed drill. Think "Roto Rooter"...

If this doesn't do it, you must remove the plenum for a thorough cleaning.

95CUTLASSSUPREME

Thanks For The Help Bill. That Was One Avenue I Was Considering. Would A Partially Clogged Egr Port Cause That Particular Fault Code? My Tech Was Leaning Toward A Wiring Problem Between The Egr And The Pcm. He Had That Recently On A Grand Prix, But It Was Causing Driveability Problems. My Olds Is Running Fine. My Tech Indicated The Clogged Port Should Register On His Scanner As An Inconsistent Flow. I Think I Will Have Him Clean The Egr Passages To See If This Solves The Problem Or At Least Eliminates Another Variable. Thanks Again Bill.

GMMerlin

Usually a code 77 is an indication of a plugged EGR passage....you can command the EGR #3soleniod on (with a scan tool) and see if the engine stumbles or cuts off completely...

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95CUTLASSSUPREME

Thanks Bill And Gmmerlin. Had My Tech Clean Out The Egr Passage Yesterday And That Solved The Problem.