RHZ is the 110 bhp version the other the 90. This information is third hand to me and has not been confirmed by an expert so, to be absolutely sure, ask Citroen UK
110 bhp This is wrong as it can be 90 bhp or 110 bhp. The 110 bhp has a pipe running from front to back of the engine between the engine top cover and the air cleaner pipe, about the same diameter as the air cleaner pipe. In addition, although I have not confirmed this, the Chassis or VIN number for the 110 has the letters RHZ in it and the 90 bhp has RHY.
I have a Suzuki Grand Vitara 2002, RHZ HDI 2.0 turbo diesel, since 5 years after i go on the speedway the truck goes on limp mode, check engine ligth comes up, codes solenoids valves, throttle position sensor, glow plug, and some other codes, replace the three solenoids valve, it keep doing the same thing, until a decide to eliminate the CATALYTIC CONVERTER, i was obstructed, it seems to be a factory defect, since NO MORE CODES, the trucks feels like new, fast acceleration, easy to start up, so the problem is with catalytic converter,