Brake problem 06 Tacoma

Hello, I have a 2006 Tacoma and recently started to have some low pedal. I thought it was in need of some brake pads, so I got new pads and new rotor. When disassemble the front brakes, the pads were in pretty good shape and so was the rotors. Anyway I replaced them both and after everything was done, the low pedal feel was still there. I never opened a bleeder valve, so there couldnt have been any air trapped but after several stormbraining ideas, we decided to bleed the system. All four corners came out clean, no air and with pressure, but the pedal still goes down. Now I noticed like the ABS module is purging inside. I dont want to have to purchase a module and not been the problem, but I dont think the master cylinder is the problem either since its putting enough pressure out and no air whatsoever. If anyone has had this experience and can help out, I would greatly appreciate it.

Again to recap:
1. bleeded system
2. system has pressure
3. pedal still goes down
4. no leaks, rear cylinders and front calipers dry
5. purging sound at ABS module when pedal pressed

Thanks again.

PS-truck is already out of warranty