just got an 02 tahoe, with so many miles on it, that im afraid to say. Anyway, I took it as a personal challenge, to make
this thing pass emissions. First try, it almost made it. Heavy on nox. Keeping in mind, that i have done almost everything
to make it pass. in that endevure, i was gonna clean the egr valve. Looked and looked, didnt find one. Come to find out that the 02's didnt have egr valves. Does anyone know how to attack the problem of slightly high nox, without an egr valve? I believe I need to bring down the burning temp, cuz when too high, excess of nox is the result.