Hi been to Honda to check car it was vibrating on tickover and missing at 1000/2000 rpm they said it will be the egr valve. i have looked at it to do it my self but this one as hexagon head bolts i seen on utube that some have nuts on studs the bolts are flush with the flange so i dont think i can get some dw40 down it the bolts have been on this car for 15 years and i dont want to snap the heads off so it looks like a job for honda on independent garage