The following description, from Wikipedia, which purports to be KE, is actually a description of the K-Lambda control method; note the reference to a "fuel injector inline with the fuel return"; that is the frequency valve of the K-Lambda.
The EHA is a component of KE, is in the fuel distributor, and varies the lower chamber pressure to adjust mixture. All KEs have O2 sensing, and mixture feedback control thereby.

From Wikipedia:

KE-Jetronic (1985–1993)

Electronically controlled mechanical fuel injection. The engine control unit (ECU) may be either analog or digital, and the system may or may not have closed-loop lambda control. The system is based on the K-Jetronic mechanical system, with the addition of an electro-hydraulic actuator (EHA), essentially a fuel injector inline with the fuel return that instead of injecting fuel allows fuel to bypass the fuel distributor, which varies the fuel pressure supplied to the mechanical injection components based on several inputs (engine speed, air pressure, coolant temperature, throttle position, lambda etc.) via the ECU. With the electronics disconnected, this system will operate as a K-Jetronic system.[1]

Commonly known as 'CIS-E' in the USA. The later KE3 (CIS-E III) variant features knock sensing capabilities.