Over the period of a number of months, I experienced the same intermittent codes. Like most of you, I cleaned, checked and even repaired some very small hairline cracks that I thought may have been vacuum leaks. I also started to avoid the "cheap" gasoline places, choosing to stick with the premium brands. I also sought out the ethanol-free fuels, whenever possible. Each and every time, the CEL would eventually return within the week.

Bottom line, I found the problem...my fuel cap. I was accustomed to replacing it to the point that it clicked, then stopping. Now I make sure to crank it down nice and tight...with 2-3 extra turns, just for good measure. I haven't had the codes in 2-3 months now (knock on wood).

So, a freebie that you may want to give a shot. Good luck!

 

I'll give that a try. I've come to assume that lean codes are just a fact of life.

 

Sounds like a vacuum leak to me.

 

just wondering what the average fix is

 

I'm experiencing this too for the last week.

Initially I had "too rich" on both banks, I found the airbox boot was leaking just before the MAF. I cleaned the MAF properly with the proper cleaner and boom it went away.........until it then returned with "too lean" codes. Now I can't get that to end, does it once per drive or so. Very annoying. The gas cap doesn't seal as well as I'd like on this, I replaced it, still doesn't impress me with the seal and I'm still getting the code just the same. I tried a amazon replacement MAF, same routine. I can't seem to find the intake leak if there is one.

I do hear a very slight exhaust leak though, except that's not new but maybe it's just bad enough to cause the issue? Though strange that the timing was after cleaning the MAF and yet a new MAF doesn't fix it.

My only thought at this point is that the exhaust leak was being compensated for by the dirty MAF readings and now by cleaning it, I've removed the buffer. I took a few screenshots of the data logs but I don't know that they'd be all that useful.

 

When you have tried everything listed here has those have not worked, (and you should try all those first) I would reset adaptive learning on the engine. Several threads on this forum came to that conclusion after every thing else failed.

Jeff

 

I've been hoping it would learn on it's own....... I wonder if my little $60 dollar scanner can reset the adaptive learning curve.