[rogoman]

Considering that both sensors are showing a DTC at the same time and that you're also having startup failures, this points to a possible charging system problem.

Consider testing the charging system first. A properly working charging system puts out about 13.2 to 15.0 volts. A battery should have a static charge of 12.3-12.8 volts. If a battery is not good, the charging system may not be able to charge properly. If a vehicle is not charging properly and the battery is good, the first thing to do is to turn the ignition switch to the "ON" position without starting the engine and make sure the charging system warning light is operating. If the bulb is burnt out, the charging system will not charge. If the bulb is OK but still does not illuminate, the circuit must be tested. If the warning lamp does illuminate, then the next thing to check is to make sure the circuit between the battery positive post (+), or fusible link, to the connection in back of the alternator is good. On Nissans, this should be a thick (approx. 10 gauge) wire to the "BAT" post on the back of the alternator. With the negative cable (-) disconnected from the battery, measure the resistance between the "BAT" post on the back of the alternator and the battery positive (+) post; the resistance should not be greater then 0.2 Ohms. It's not uncommon for this wire to get corroded and burn up, creating resistance in the circuit. So, before assuming an alternator is bad, make sure this circuit is good and battery voltage is getting to the alternator. It's also important to make sure the alternator belt is tight and not slipping and the battery connections are clean and tight.

When a charging system is not charging, or overcharging, a lot of "strange" things can occur. It's not uncommon to see a multiple of stored trouble codes in the ECM memory. So, whenever a car is setting a multiple of trouble codes, idling funny or stalling, or anything out of the "norm," test the charging system before you start pulling hairs!