You Faaaaiiiilll!

Feeling emboldened by the successes of diagnosing vehicle problems, I decided to take the truck to the emissions testing center to see what would happen. We had a new oxygen sensor, a new throttle position sensor, additional knowledge of what was supposed to be what on the truck, what could go wrong?

First off, they did a lot of looking under the hood trying to figure out what they were looking at and to see if the emissions equipment had been tampered with. Some Father Time looking tech pulled the truck onto the dyno to do the rolling test, promptly stalled the truck and then couldn't start it again. They pushed it off the dyno and said they couldn't get it started again. Uh . . . it is a carbureted vehicle, you have to hit the gas to start it again. We don't have that fancy fuel injection. I walked to where they pushed it, hopped in and started it right up. They said I could go back through the line and try again . . . thanks.


After going back through the line and reminding a different tech that it was a carbureted vehicle, the truck was off and testing! Hydrocarbons-check, CO-check, Gas Cap-Check, NOx-FAAAAAAAAAAIIIIILLLLLL!!! It tested at 9.8776 GPM with a limit of 6.000 GPM allowable. What does this mean? A little research shows tells me that the temperature and/or pressure in the combustion chamber is high creating oxides of nitrogen. This can be caused by timing issues or the EGR valve not operating properly. The EGR (exhaust gas recirculation) valve puts exhaust back into the system basically as a space filler. Exhaust is relatively inert so less oxygen translates to cooler combustion chamber and in turn, less NOx output.

We have some parts on the way already. The replacement idle control motor should show up by the end of the week. After a little searching, the EGR valve is cheapest locally which is a plus. We have 10 days to go retest for free. Between now and then, we should be able to clear all fault codes with our replacement parts and hopefully get the timing checked by somebody who knows what they are doing. Once we obtain a passing grade on emissions, we can take the next 1 year and 11 months to fix the issues deemed "optional" . . . things like a missing tailgate clip, no horn, and a fuel gauge that goes from F to 1/2 pretty well and then drops to E. Good times . . .