2001 Ranger OBD-II Codes

HI Guys, Newbie here.
I have a 2001 Ford Ranger 4cyl 5spd 2wd with the check engine light on.
I took it to the parts store and he plugged a scanner into the dash. I believe it was a obd-II code reader. The code he got was P1537 He could not pinpoint the problem any further than that and suggested I try the Ford dealer. Can anyone tell me what this code means and is it something that I can replace myself?

http://www.fordforums.com/showthread.php?t=94502

Some info there on it.

http://experts.about.com/q/Ford-Repair-811/P1537-P1538-P0161.htm


http://www.obdii.com/ubb/Forum1/HTML/002405.html


Thats what i could find. Anything beyond that we need a pro lol im just a shadetree with my first Ford after owning 2 Gms.