SVX Won't Start... Fuel Pump?

[daristotle]

My SVX died on me in the middle of road yesterday and wouldn't start. Had to get towed back home. It cranks and sometimes catches but then immediately dies. (But, mostly just cranks.) It has done this twice before this past summer. The first time it started back up again after 10 or 15 tries. The second time it started up after I had a friend come over to look at it and we had barely begun to diagnose it. I've checked the fuses, replaced the battery, replaced the fuel filter, and tried swapping the MAF sensor with a known good one.
What should I do now? Where can I check to see if the fuel pump is getting voltage? (I think it has a relay under the steering wheel.) Or is it probably something else entirely?
Thank you for any help.

UPDATE: I just got code 37 for the oxygen sensor. Would this cause my problems?