Well, it just about passed the test this year, the HC's were high - .66 Vs the .80 limit. The NOx and Co were low, less than 30% of the limit. It's got a recent cat, new injectors, and the motor was reringed a few months ago. Mileage is generally horrid on the thing - low 20's in town, mid 30's on the highway. No trouble codes, naturally... I'm stuck here, guys. My only two guesses are the ever popular O2 sensor, or the fuel pressure regulator on the rail. The mechanic claims the EGR valve might be messed up, but I thought that was an NOx thing,. So, am I at least somewhere on the right track fingering the EFI, or am I totally lost here? Oh yeah, the plugs are a bit old - time for new ones?
