what is a engine code PO135 on a 2005 dodge stratus?

O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

O2 Heater element resistance is high....... Internal short or open in the heater element ......... heater circuit wiring high resistance open or short to ground in the wiring harness........... Possible Solutions: Repair short or open or high resistance in wiring harness or harness connectors Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)

any chance an undervoltage condition at the ECU caused this "fault" to appear?...H25?

And good morning

Well, possibly yes Judge. But I read the entire article and it seems most likely it's in the 02 sensor itself, or the heating element, it is a heated sensor..all those other possible scenarios far less likely, but to answer you ..yes, maybe. ECU's don't like non constant voltage and may have sent the wrong signal to the OBD

yes...heated element...like a heated elephant is going to suck the power...if marginal may affect the delicate ECU...who knows? if I could experiment by putting a brand NEW battery in that would know if the theory meets the practice~

True. Would be nice to know age of battery, it's an '05 so possibly OE