...doesn't exist. Emission cutpoints are a function of vehicle weight, and the data for all OE models is in a BAR database. A 300E has higher cutpoints, not because of the larger engine, but because of the higher weight. The BAR Web site has a page on how to compute cut points based on test weight, which is usally curb weight plus about 300 pounds. It's listed on the test report.

Technically installing a 3.0L engine in a 190E 2.6 is an automatic failure because it was never emsssion certified by the manufacturer, however, since the engines appear essentially identical, the test tech will likely never know.

Assuming the fuel and ignition systems, and emission equipment is is good working order, emissions will be about the same at the original 2.6, but the whole M103 engine family has been tagged by BAR as "high emitter profile", and there have been many discussions of "tricks" to get them through, particularly shorting the R16/1 resistor and plugging the vacuum advance.

Duke