Question

P1148 and p1031 NISSAN codes - 04 titan. What is the problem?

Answer 1

P1148 = Closed Loop Control Function Bank 1 = https://www.autocodes.com/p1148_nissan.html

P1031 = Air Fuel Ration Senosr 1 = https://www.autocodes.com/p1031_nissan.html

There is a bulletin for those code. The bulletin suggest to reprogram the Engine Control Moduel (ECM) to fix the problem.  Unfortunately only the dealer may be able to reprogram the ECM for you.