Howdy from Texas y'all, Jeep Liberty Renegade

[cRiPpLe_rOoStEr]

Originally Posted by crashnzuk

I don't know about propane, but in my experience with CNG, the NOx is very high. We used to have quite a few CNG vehicles at work from factory build Dodges to retrofit Fords. One thing they all shared come smog check was NOx right at the ragged edge of failure.
Travis..

It might have some relation with the fuelling system used in the vehicles.