Head gasket shot?

[Frank Enstein]

Time for new O2 sensors. At least the upstream ones. Drive it for a few days to make sure all the coolant is burned off.

Low voltage = Lean or dead O2 sensors.

 

[Schurkey]

Coolant does kill cats but I see cycling, what am I missing?

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Took me awhile to see it. In fact, I didn't notice it until I happened to see the double-traces in the other picture.

There's supposed to be TWO graph traces--a solid line for Bank 2 Sensor 1 (upstream) and a dotted line for Bank 2 Sensor 2 (downstream)

The downstream, dotted-line graph is flatlined, just above "0". Hard to see, below the uppy-downy solid-line graph.

It's dead, Jim.

Either the sensor has failed, or there's wire-harness problems. Either way, that's gotta get fixed. "I" would cram four sensors in the thing, and hope for the best. Deal with wire-harness issues on the Flatliner, if the sensor didn't fix it. But maybe I'm too quick to condemn "experienced" O2 sensors. So maybe just replace Bank 2, Sensor 2 (downstream)

By comparison, the Bank 1 sensors are both moving about the same amount.

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I'd expect that with a healthy catalyst, the downstream (dotted-line) would be moving less vigorously. The graph might show some movement, but not as much as the upstream sensor.

I'd drive the thing awhile, especially under load/high speed. MAYBE that catalyst will come back to life. Maybe not. As is, it's not doing anything, which is why both O2 sensors have about the same voltage swings.

 

[east302]

Thanks guys, sounds like a plan.

 

[Supercharged111]

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Took me awhile to see it. In fact, I didn't notice it until I happened to see the double-traces in the other picture.

There's supposed to be TWO graph traces--a solid line for Bank 2 Sensor 1 (upstream) and a dotted line for Bank 2 Sensor 2 (downstream)

The downstream, dotted-line graph is flatlined, just above "0". Hard to see, below the uppy-downy solid-line graph.

It's dead, Jim.

Either the sensor has failed, or there's wire-harness problems. Either way, that's gotta get fixed. "I" would cram four sensors in the thing, and hope for the best. Deal with wire-harness issues on the Flatliner, if the sensor didn't fix it. But maybe I'm too quick to condemn "experienced" O2 sensors. So maybe just replace Bank 2, Sensor 2 (downstream)

By comparison, the Bank 1 sensors are both moving about the same amount.

You must be registered for see images attach

I'd expect that with a healthy catalyst, the downstream (dotted-line) would be moving less vigorously. The graph might show some movement, but not as much as the upstream sensor.

I'd drive the thing awhile, especially under load/high speed. MAYBE that catalyst will come back to life. Maybe not. As is, it's not doing anything, which is why both O2 sensors have about the same voltage swings.

I see it now, that thing is pegged. When I flipped that dually the exhaust stunk like rotten eggs for a while (powertrain had sat a few years). After some fresh plugs and a couple of 30 minute drives it started clearing up and there was zero smell by the time I sold it.

 

[Ruff Idol]

Sounds like that engine's hydraulic now.

LOL! Got that right