Guide :Maintenance & Repair : 1992 GMC Suburban
so my 1992 5.7 suburban's egr valve is opening and closing every 5-10 seconds
So I have replaced o2 and cleared code, no new codes, EGR valve is opening and closing every 5-10 seconds cold or hot causing engine to surge at idle runs fine at speed, any ideas ? I have not replaced the EGR controller yet, but I have cleaned both EGR and IAC. I can see the EGR cycling and it is the cause of the surge if I unhook vacuum line it stops of course.