robertbartsch

I've been throwing a PO109 code (No signial O2 sensor - Bank 2, sensor 2) for a while now and I need a fix.

Two years ago I installed LT headers without rear 02 bungs. To fool the PCM into believing I still had rear O2 sensors, I also purchased 02 simulators from Thunder racing that worked fine until recently.

Since I also have LS1Edit, I downlowded the current version of my PCM to my PC this weekend and looked to see if the two tests for the 02 sensors had been turned off. Since they had not, I revised the program to eliminate the 02 sensor checks and up-loaded the revised program to the PCM.

Unfortunately, after a few test sessions in the car the "service engine soon" light returned.

Is there a fix for this in LS1Edit that I am not aware of or do I need to replace the rear O2 simulators?

Thanks...

robertbartsch

These are the rear O2 codes.

P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2
P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
P0140 HO2S Circuit Insufficiency Activity Bank 1 Sensor 2
P0141 HO2S Heater Circuit Bank 1 Sensor 2
P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2
P0158 HO2S Circuit High Voltage Bank 2 Sensor 2
P0160 HO2S Circuit Insufficiency Activity Bank 2 Sensor 2
P0161 HO2S Heater Circuit Bank 2 Sensor 2
P0420 Catalyst System Low Efficiency Bank 1
P0430 Catalyst System Low Efficiency Bank 2

Don't turn off the affected DTC codes - that will just trigger a failure result if you have ODBII testing in your area.

To get around the ODBII testing now being done, do the following:

For each DTC code you want to "avoid", just set the related error result code to "X" using LS1 Edit. Leave the test itself on. The net effect is that the ODBII tester sees the test as being "ready", but the "X" error code instructs the PCM to not throw (or even store) the DTC error code.

Deleting (i.e., turning off) DTC codes will show as the test being "not ready" at inspection time.

Just in case anybody is curious, here's what the various error result codes mean:

Type A = MIL triggered on first occurance
Type B = MIL triggered on second occurance
Type C = No MIL triggered (DTC will be stored, but no MIL will occur)
Type X = turned off (no MIL will trigger and no DTC stored).

racecar

Excellent Advice

robertbartsch

Thanks,,,,

From time-to-time, I do my own research and it is amazing how much I can learn...