Running rich?

[99BB3500]

ok so I did some logging today. I cannot see the voltages of the upstream o2 sensors other than them being “ready”. I did however notice that the issue starts when the fuel system enters a closed loop. Last time I did a fuel pressure test it was at 45 psi with a max of 50-51psi. That’s when I changed the fuel pump. I did not change the fuel pressure regulator yet but I’m sure that’s in the works soon. Here are some more pictures

EDIT: my fat thumbs And words don’t really get along

 

[Supercharged111]

I'd be shocked if you can't find the voltages, I've used one of those before. Instead of watching the graph, assuming voltages aren't in there, go over and monitor the voltages real time. Once you see it peg 0 or 1000 you've found a bad sensor.

 

[99BB3500]

I’ll check again. Ran a data display as I was driving

 

[99BB3500]

Both sensors at idle are .535V. Pressing the gas quickly both voltages dropped to .475 on the left and .435 on the right

 

[99BB3500]

You must be registered for see images attach

 

[stutaeng]

I don't the upstream sensor oscillating...

It stays at a constant voltage under idle?

 

[99BB3500]

I don't the upstream sensor oscillating...

It stays at a constant voltage under idle?

Yes. At idle unless I hit the gas it stayed at .535 volts

 

[99BB3500]

This was also after sitting for a few hours and in an open loop.

 

[stutaeng]

Does the other side oscillate?

I had an upstream do what you are describing on my 6.0/2500 suburban. I think I was getting an O2 sensor code on mine though. I haven't driven it since, but I changed both sensors on that side.


What does it do when it goes into closed loop?

 

[99BB3500]

Loses a small amount of power and runs lean. What the picture is is both upstream sensors on both banks. Downstream isn’t shown