What O2 sensors are you using. Brand and where did you buy them from.

Simple Question as I have been having an issue with a couple of NTK ones I bought and wanted some input from other 4.X owners.

Especially if you are running a 93 Elderado with the dual O2 setup.

P.S what years or model 4.9's used the 2, O2 system.

Oh come on guys, are ya really going to tell me that not a single person knows what brand O2 sensor(s) are in there motor.

ac delco. I compared them a few years ago and liked them better than bosch. Now maybe they're the same?