Walmart uses a proprietary scoring system. No one really knows what formula they use, but the score range is a dead give away. As far as what CRA they pull, it's a YMMV type of thing. Sometimes they pull TU, sometimes EX. The FICO score they provide when you are approved and sign up for paperless billing is a TU FICO 08. They generally pull TU for CLIs.
July 2013 score: EQ FICO 819, TU08 778, EX "806 lender pull 07/26/2013
Goal Score: All Scores 760+, Newest goal 800+
Take the myFICO Fitness Challenge
Current scores after adding $81K in CLs and 2 new cars since July 2013
EQ:809 TU 777 EX 790 Now it's just garden time!
June 2017 update: All scores over 820, just pure gardening now.