Wait a minute.. now that I didn't know. Only diesel's have nox sensors on them? Well I've been using regular gasoline during my last few visits at the gas station so I'm sure it's not diesel. But I'm surely not out of the woods just yet either because now I'm wondering have the cats gone bad. I checked another website where I inputted p1309 and here's what I got:

"When you fill your car with gas, the vapors in the tank get forced into a canister filled with activated charcoal. Also, on a hot day as the gas heats up and vaporizes, those same vapors push into the canister where they're stored. But the charcoal can only hold so much vapor. At some point it has to be emptied. The emptying process is called canister purge."

I did mention that my problem seems to happen particularly during warm weather so I'm now starting to lean in this direction. Just how do you replace the charcoal canister, or could it be that I should replace the canister purge, or some call it the fuel tank breather?