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View Full Version : Getting DTC 0172&0175, WBO2 bounce



Ram Air IV
September 13th, 2009, 08:06 AM
Hi, My LQ9 in my Firebird -68 does not run as expected, First of all I get the DTC P0172 and 0175. Second, the WBO2 bounce from 12 to 18 AFR and it correspond to the short term fuel trim value that jumps between 0 and -25%. This occures when I drive at 40-80 km/h with constant TP. I have moved the LH O2-sensor to the RH-side and vice versa and it did not change any thing (I thought that I should get DTC 0171&0174). The WBO2 is located after the exhaust cross-over. Look att the screen dump from EFIlive. I have made new harness with longer cables in order to re-locate the PCM.

5.7ute
September 13th, 2009, 07:13 PM
First up, the AFR will bounce when closed loop fuelling is active. Second, once closed loop is enabled, your LTFT are pulling a heap of fuel. This would be setting your rich trouble codes.
I would be turning off closed loop, and going through the AutoVE procedure to bring your fuelling into line. Then automaf if you are still running one. Then go back to closed loop & see how your fuelling is.
Might not hurt to post up your tune file if you need help with these procedures.