LG4 Engine,

Put on a new Fuel Tank Cap - The old one was "Ok" but this one was way tighter and seemed to fit better, it was a GM original part.

Next drive i get code 44, i had just washed the engine, and i actually did powerwash around the carb, it was filthy.

So is it the cap, or the power washing, that did it?

 

Did this show up before or after getting your smog inspection issues sorted out?

 

It was after

 

I ask because they test both the fuel cap and the fuel vapor return system (or whatever it's called). A vacuum leak in this system light cause a lean condition and your Code 44.

Since both were tested and passed, I would look elsewhere. Take the air cleaner off and see if you might have dislodged a vacuum hose when you pressure washed the engine.

 

Weird - didn't come up on tonight's drive home....