well i decided to try and squezze the most out of my 92 190e 2.6
i hook 1 meter to the eha valve and another meter to x11-pin-3.
lambda reading was 42%to 48% .but the eha reading was +1.19
which is lean, but rich reading at x11 i figuire i lost a little gas milage so why not go for the sweetspot. at this reading when i
rev the engine around 2000rpm the lambda reading would creep to 68%to89% fluctuating back and fourth which is very lean reading i adjusted the mixture screw until at idle eha read from
-0.54ma to -1.32ma= a little rich and lambda reading from 39%to49% then when i rev the engine at 2000rpm the lambda reading went no higher than 55%to64% and eha reading +1.17=lean turn engine off let cool for a few hours the re tried it setting stay at what i left it let the car cool off again the 2 hours later when i drove the car taking off you would feel torque right off keeping you back in the seat.well worth the 2 hours of adjustment next step was going to be adjusting the screw on the eha valve to richen it but didn't need to go that far maybe now i can get a reading on my plugs 800 miles later and the porceline is still white hope this helps enjoy from the sandpile