Once again my WJ (04/4.0 w/50state emissions/Manufacture date Feb/03) has DTC's:
O2 Sensor Heater Circuit (Bank 1 Sensor 1)
Oxygen sensor heater element malfunction.
O2 Sensor Heater Circuit (Bank 2 Sensor 1)
Oxygen sensor heater element malfunction
I've replaced O2 sensors twice since I've owned her, the last time being about 3 or so years ago. Not wanting to spend the money again for new O2 sensors I poked around and found a TSB
for erroneous DTC’s relating to a failure of the oxygen sensor heater on WJs built prior to June 02, 2003 and equipped with a 4.0L engine. The description seems to fit. It's made before 6/03 and I do occasionally start it up let it idle to warm it up in the mornings for my thermoregulationly challenged GF.
However, the dealer wants $120 just to hook up the DRBIII scan tool to see if it may have already done by the PO. If it does need it, they'll flash it without additional charges. But if it doesn't, I'm out $120.
My questions are:
Has anyone had the flash done and it did indeed fix their issue?
Should I see if I need flash/get done first or replace the two upstream O2 sensors first? Either way I could end up having to pay for both.