Update on the EGR related driveability issues... I miss the "burp"!
If you've been following this thread, you know the car came with some pretty serious hesitation / bucking / herky-jerky engine issues under light load when transitioning into lean burn.
Back around post 51 (
http://ecomodder.com/forum/showthrea...tml#post239474 ), I mentioned I cleaned the EGR manifold, and later the EGR valve itself.
I also ran a container of combustion chamber cleaner through the first tank of gas.
I can report the problem is 100% fixed. Ironically, I'm ever so slightly disappointed about this!
My butt-o-meter is no longer able to feel the transition in and out of lean burn! I almost wish the tiny lean burn "burp" / stumble that existed right after doing the EGR fix was still there. But, nada. Can't feel the NOX purges any more, either.
Unfortunately, minus the burp, I have to visually monitor the instant fuel economy display to be able to know for sure when lean burn is active & how deep into it the engine is. A nice audio signal would be useful!
Silly to complain about a perfectly functioning lean burn system in an engine with 270,000 kms on it!