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2016 Chevy Tahoe 5.3 130000 miles p0420/0430 I'm old school,
2016 Tahoe 5.3 130000 miles, p0157 o2 sensor circuit low voltage bank2 sensor2 changed sensor no different. Now i am getting same code with p2099 post catalyst fuel trim system to rich bank 2 with a random multiple cylinder misfire detected. Also getting p0420 p0430 Catalyst system efficiency below threshold bank 1 and 2. Any help would be great, if you need more info on my end to help with this condition let me know i will try and get it for you. Another thing to add to this is I removed all plugs and the are all burning clean with no black deposits on them. Thanks
Your problem is in the P0157. You have a wiring issue. The other codes are a result of the 157.
Start by inspecting the wiring harness for that sensor. Look for contact points where the wiring could come in contact with metal. Don't pull the wiring, gently inspect looking for wear to the harness and individual wires for the sensor. The sensor will have 4 wires. 5v ref, signal, 12v power and a ground.
The connector can have a bad pin connection. As you replaced the sensor, the sensor side of the connector should be Ok inspect the harness side of the connector.
Don't be a parts changer. You found that already. The sensor was good the wiring is the problem.
"an open mind let's knowledge flow in and wisdom flow out for a man who has neither never listens to those who have both".
Being wrong doesn't bother me, it's being right and not understanding why that does
Thank you for the reply, checked the pin connector, looks like new with no broken pins or corrosion. I plugged it back into sensor look on scanner o2 sensor has voltage, drove it for about an hour last night ran fine, set three of the eight monitors. Parked it for the night went to start it, started fine, then it started running rough. Checked for vacuum leaks around intake, none.
Unless your stft and or ltft are high positive numbers and get better at higher rpm, looking for a vacuum leak is a waste of time. You would get a P0171 and 174 if they are too high.
Unplug the b2s2 sensor. Is the voltage reading the same? If so you have a short in the wiring of that sensor. That's why replacing the 02 did not fix the problem.
"an open mind let's knowledge flow in and wisdom flow out for a man who has neither never listens to those who have both".
Being wrong doesn't bother me, it's being right and not understanding why that does
I agree with Scanner John and would also add that depending how quickly the code sets, I like to check for an exhaust leak in the area of the o2 for o2 low voltage codes..
If it sets immediately on the first key cycle without driving it, then this won't be the case.
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