[maxwithershins]

I have two books here that contradict each other concerning O2 sensors on these cars.

One says the '93-'95 LHs have a non-heated O2 sensor on each manifold (2 total) and the '96 - '97s have four *heated* sensors (upstream / downstream). This same book then contradicts even itself and says the '93 - '95s have 2 *heated* sensors.

What's the truth?

[DrDodge]

thats cause starting in 96, chryslers went to OBD2 computer systems, thus 4 heated sensers, there heated to get to operating temp quicker, thus reducing emissions, before 96, they had OBD1,, down stream sensers were not used, in most cases

[maxwithershins]

That's what I figured. And the '95 and earlier were also UNheated, correct?

I finally have access to the garage, so I'm gonna go pull the car in and try to get this thing figured out, and see what it's really equipped with.

I keep blowing Fuse 20, which I'm reading also provides power to the O2 sensors. But I can't imagine a circuit with a 10A fuse could be providing heater power!

So far the A/C Clutch relay, Low-Speed Fan relay, Hi-Speed Fan relay, EGR solenoid, MTV solenoid and Purge Canister solenoid (all powered via Fuse 20) seem to be OK. And the circuit (wiring) itself doesn't seem to be shorted.

And I'm not getting any O2 Sensor-related codes, either. Go figure. Thing's driving me nuts!

[maxwithershins]

Nope. Checked 'em out in person now. Two O2 sensors; both heated. Both heaters test out at ~6.5 ohms, which puts them within what three different manuals say is the "acceptable" range of 5 - 7 ohms.

So, still no clue about what's been blowing Fuse 20. There is *nothing* connected to that circuit now ... and the fuse hasn't blown. Time to start checking every single component that plugs into it ... for the third time. Grrrr.