rich condition HELP! o2 mv dead at 930mv bank 1

[ctsv2011]

2010 Cadillac ctsv
out of nowhere my car is running with a rich condition, nothing has changed besides some bullet style resonators added to the exhaust . can anyone help me out with the data supplied it looks like it started with both banks reaching -25 % then bank 1 completely stopped reporting fuel trims. my wideband is on bank 1 side and can confirm afr is going into the 9:1 . im guessing o2 sensor is toast as im having trouble 1 day after having exhaust work done. 2 days ago car was running perfect no MIL light is on so not sure on my 02 sensor diagnosis.

any advide is appreciated

[blindsquirrel]

Unplug the sensor, it should go to the default bias voltage of ~450mV.

Welding can often backfeed voltage to places it should not ever be. Could have fried the sensor, or worse.

[ctsv2011]

Unplug the sensor, it should go to the default bias voltage of ~450mV.

Welding can often backfeed voltage to places it should not ever be. Could have fried the sensor, or worse.

so just unplug it and log it with scanner to check voltage correct? never knew you could check that way i figured wouldnt see any data at all unplugged

[blindsquirrel]

The ECM supplies 450mV on the signal line, the sensor just drives that voltage higher for 'rich' or lower for 'lean'.

[verlon]

Your o2 sensors is ok.
MAF is ~35% higher than VE Airflow. Force MAF Failure and check fuel trims.

[ctsv2011]

Your o2 sensors is ok.
MAF is ~35% higher than VE Airflow. Force MAF Failure and check fuel trims.

it was tuned a while ago maf only ve disabled, this problem just started yesterday

[ctsv2011]

The ECM supplies 450mV on the signal line, the sensor just drives that voltage higher for 'rich' or lower for 'lean'.

unplugeed and checked with scanner shows .450 volts i then logged the car starting and running 30ish seconds after start up i can see the mv at 450 on both banks then it goes closed loop and my bank 2 starts switching but not my bank 1. are these sensors proving to be good still my wideband is reading in bank 1 as well not sure if you can see that when you open log with your channels

[blindsquirrel]

Wideband seems to agree with what the B1 NB is saying... NB dips lean, WB also reads lean, NB goes richer WB goes richer.

screenshot.15-03-2023 18.09.59.png

Drippy injector? I'd pull spark plugs & inspect.

[GHuggins]

You sure the exhaust isn't restricted now?

[Alvin]

The o2's look OK to me. They are trying to pull fuel from the car.. Not like a sensor error where they are adding when not needed.

I'd say maybe those resonators flow so much differently than what you had that the car might need to be retuned. What exactly did you put on it? No chance its installed backwards or something?