ADD if “oem” 0-5v Maf scale is used, true plug n play, <500 hp. AVE if ecu is tuned for “ dual pop” 0-2.5 V Maf signal, >500hp These translators cut each of the Maf voltage in half. You need to ADD them for a “oem” 0-5v signal. You need to AVE them for a 0-2.5v signal to the ecu allowing the system to meter more air in the “dual pop” mode.