So a quick glance over the supported vehicle list does not show the 03-04 Mercury Marauder as a supported vehicle...but the drivetrain is the same as a Mustang Mach 1 which is supported. I do see that Crown Vic/Grand Marquis are not supported before 05, so perhaps there was a PCM change in 05 and the Marauder uses a Panther platform PCM to control the DOHC 4.6 rather than the Mustang Mach 1 PCM
Thanks in advance.