I keep getting a code p0677 glow plug #7 circuit fault. Does this mean that i have a bad glow plug? Truck starts fine and runs great except for the rough idles at times. No check engine light has ever come on. Recently put the egr delete on my truck and i have read some post and it says this fault can be caused from excessive egr failure. Is this fault just from the delete kit? Also have codes P0403 0405. I figure these are thrown due to the fact the egr is no longer hooked up.