Like I said before, the resistance is in the boots, not the plug. You are creating waaaaay too much resistance with the resistor plugs.

Why don't you follow all of the advice that you'll find on every thread about plugs? Only use original Bosch copper plugs, non-resistor type.

There are now so many variables since you've changed so many things that it's hard to tell what's wrong.

You had a code for an egr valve. You cleaned the tube and the egr valve.

However, an egr valve can't be cleaned. The diaphragm either opens or closes normally, or they start sticking (in the open or closed position) or they get stuck permanentyly (either open or closed).

Since you still have the egr code, why don't you change the valve?

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".