05-19-2014, 10:36 PM
what code?
the rear 02 signals are very complex set of rules.
the sensors are different.
the rear sensor is only a CAT monitor, the cat will burn all excess fuel and oxygen, as it exits the cat. a completely different usage.
if the ECU sees the Rear 02 hunt it knows the cat is missing or rodded out. or totally dread. (or bypassed)
and throws DTC 420 to warn you of that fact, called the Lazy cat failure.
here is my 02 sensor buy page
http://www.fixkick.com/sensors/OxyGen_se...#oxy-parts
i cover the front only in my matrix table.
but the bosch tables are clear.
4 sensors. 2 for PNP and 2 for Universal (bare wires)
http://www.boschautoparts.com/VehiclePar...inder.aspx
(05-19-2014, 11:39 AM)gorkyb Wrote:the rear 02 should not hunt. (if the cat is good) That hunting in front 02 is the AFR in closed loop mode,, hunting constantly for perfect AFR. Sthoch.(05-19-2014, 06:38 AM)gorkyb Wrote: Car seems to drive normally however this code is stored, o2 sensor is only a few months old
Looking at the OBD2 scan, it looks like the O2 sensor after the CAT is bad, it is stuck at 0.04V, it is not hunting. I see RockAuto differentiates sensors between upstream and downstream, I used the same Bosch downstream as I put upstream when I did work on the exhaust, am I using the right sensor downstream?
the rear 02 signals are very complex set of rules.
the sensors are different.
the rear sensor is only a CAT monitor, the cat will burn all excess fuel and oxygen, as it exits the cat. a completely different usage.
if the ECU sees the Rear 02 hunt it knows the cat is missing or rodded out. or totally dread. (or bypassed)
and throws DTC 420 to warn you of that fact, called the Lazy cat failure.
here is my 02 sensor buy page
http://www.fixkick.com/sensors/OxyGen_se...#oxy-parts
i cover the front only in my matrix table.
but the bosch tables are clear.
4 sensors. 2 for PNP and 2 for Universal (bare wires)
http://www.boschautoparts.com/VehiclePar...inder.aspx
http://www.fixkick.com