Yet another update and hope this one is the final update.

first of all, I have replaced the engine oil filler neck and the cap with a brand new OEM parts and….. the light came back again.

what I did next was to take the air intake off and apply sealant to every joint before tightening the clamp. Did another smoke test to make sure there is no leak.. put everything back together.

and…. The light came back on again..

I did another leak test again to make sure I did not miss any small leak with extra lighting in my garage and I found a very tiny leak still coming from the MAF sensor.
I took the MAF sensor out, cleaned all the sealant applied earlier. While doing this, I have noticed that the new MAF that I have is not Denso, but Dephie.

all this time, I thought it was a Denso brand… funny…

so I decided to put the old Denso back on the car since lot has happened since day one.

-Oxygen sensors, all four of them
-Crank case vent Valve
-Resealed the gasket on EGR valve and Throttle valve with gasket maker.
-oil filler neck and cap
-reset adaptation
-sealed the air intake pipe.

But this time, since I know that there is a leak between the intake pipe and the MAF sensor, I wrapped some teflon tape over the rubber ring on the MAF sensor before putting it back.

and to my surprise, the engine light has not came back for the whole day!!

I will have to keep monitoring it, but since the day one, the light always came back on second cycle. So, even if the light decides to come back on after a few days, there is something different this time.

But I am not sure if it was the leak or the Non-Denso MAF that was causing the lean code. It goes without saying that the best way would be to apply teflon tape on the Dephie unit and put it back on the car to find out… butI have no strength left after the 2 month battle with the engine light

 

That's good news! Thanks for updating the thread