Any ideas?

Had the tires set to 34, 31, 29, 26 psi and then did exactly like the DIY threads said.

The light was blinking on/off about every second or so, started the car up, and drove it around for ~20 minutes >25mph.

The light went off, then after awhile went on and stayed on.

Went and pumped air into the tires. Brother then needed to take his car somewhere so I was unable to drive it until the light went off.

Drove it again today and after maybe 20-25 minutes of driving at 60-70mph the light came on and stayed on.

Went off after turning the car off and came back on when driving it again later. Checked the hot tire pressure and all of them read 36-37psi.

 

You have a flaky TPS and the chances are the battery is failing. Best advice, but a new OE set of TPMS from Nissan and have them installed. I was told by a reliable source not to buy ebay sensors, although cheaper they'll cause you continual headaches!
Gary

 

Just hit the thank button.

Appreciate it. I read someone had Infiniti charge like $120+ for one TPMS sensor...

Guess I'll check with Nissan and see what they quote it at.

 

Sounds like a faulty sensor. We have them as well if you can't find a replacement.