Jeep Wrangler Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I have recently acquired a 2012 3.6 and it originally had the P0420 which I cleared. I however get the downstream values above 3V where I expected 0.47V? Even on the 0-1V scale I got over 0.6V. I do smell it’s running rich. What does this mean, after clearing the P0420 it seems to have stayed away but I am concerned with the running rich smell?

I have changed the oil and filter so will go on to do the oil pressure switch next to try and get rid of the P066D unless there is a way to confirm if it is the pump or sensor?
 

Attachments

·
Registered
Joined
·
2 Posts
Discussion Starter #2
P0420 and P06DD - errors on JScan

I have recently acquired a 2012 3.6 and it originally had the P0420 which I cleared. I however get the downstream values above 3V where I expected 0.47V? Even on the 0-1V scale I got over 0.6V. I do smell it’s running rich. What does this mean, after clearing the P0420 it seems to have stayed away but I am concerned with the running rich smell?

I have changed the oil and filter so will go on to do the oil pressure switch next to try and get rid of the P06DD unless there is a way to confirm if it is the pump or sensor?
P06DD apologies
 

·
Premium Member
Joined
·
510 Posts
What you are seeing for o2 sensors is normal. Here are some snippets from the service manual.

“The 4-Wire Oxygen Sensor (O2) is equipped with a galvanic battery that typically generates a voltage signal between 0.0 volts and 1.0 volts.“

“A bias voltage in the Powertrain Control Module (PCM) shifts the signal voltage to fluctuate between 2.5 volts and 3.5 volts, depending upon the oxygen content of the exhaust gas. When a large amount of oxygen is present (caused by a lean air/fuel mixture) the sensor produces a low voltage. When there is a lesser amount of oxygen present (caused by a rich air/fuel mixture) it produces a higher voltage. By monitoring the oxygen content and converting it to electrical voltage, the sensor acts as a rich-lean switch.”


A lot of times they use bias voltage as it can help the computer or technician troubleshoot. In certain cases you may have 0 volts without a bias voltage. It could be normal or or it could be break in wiring. With a bias you would alway expect voltage. So if you aren’t getting it you may have a wiring issue.
 
1 - 3 of 3 Posts
Top