Hi Guys, I have a 1997 E300 Diesel, I recently cleaned out my air manifold & also the cylinder head ports, very carfuly, I might add. I could not believe the amount of carbon in the air manifold. So... based on this finding I set out to put a blank flange in the EGR valve & temporally remove the flap on the valve immediately before this, just to experiment but, Check engine light came on. Any ideas as to why? I read somwhere that it is a delicate balance of negative pressure in the manifold & any fluctuation will cause the light to come on. I welcome any input, thanks.
OBDII knows when the EGR valve is commanded open, and knows what the corresponding change in exhaust mixture should be. The only way you could remove the EGR would be to reprogram the computer. Don't know if that is even possible on these cars.
Mercedes is not too friendly with releasing info about set ups in their cars.
On my 97 E300 I used to have famous surge, when the intake flapper was doing crazy thing.
I plugged the hose operating the flapper, what after some driving triggered CEL.
I reconnected the hose back and for last 8 months the surge is gone.
Still trying to figure out what happen there, but only when I have a cold one in my hand.
How does it know anything about the exhaust mixture?
Oh, diesel... didn't see that the first time. It's been a while since I have even done anything with EGR on a gasoline engine, but I'm sure that OBDII can interpret EGR operation from its other sensors.
Oh, diesel... didn't see that the first time. It's been a while since I have even done anything with EGR on a gasoline engine, but I'm sure that OBDII can interpret EGR operation from its other sensors.
I believe that too, and I know exactly what sensors are involved on the turbo 606. However, I have no idea what sensors are involved on the NA 606.
EGR Valve bypass 
Linear Mode
