High NOx at 15 MPH smog test

I usually replace my plugs at 15-20k doesn't hurt, I get those plugs for about 2 bucks each through a hook up.

 

Thanks for the good advice everyone. My truck passed. Here's the latest spreadsheet and what I did to prepare.

-Changed the oil and filter
-Changed the spark plugs and wires (the no. 2 spark plug was rusted to the boot)
-Put five ounces of Seafoam into the vacuum line
-Filled the gas tank with 89 octane
-Drove the truck for 65 miles immediately before the test at freeway speeds

On a side note, remember that I replaced the MAF sensor after the 2010 smog check because it failed on me.

I don't know what made the biggest difference here but at least it passed. That's all I care about.



Values in red are the maximums.

 

You are well below the maximums. You sir have a truck in good running order.