Posted: 7/3/2007 7:12:46 PM EDT
| My '98 Suburban freakin failed smog today. Passed the visual and the sniffer, but failed due to a bad oxygen sensor. "Bank 2 sensor 1". So which one is that? The one on the passenger side of the motor in the exhaust manifold? |
When they do the emissions test on our cars out here in CA they pull all the codes. Mine had an error code "PO155 O2 Sensor Heat Fault (Bank 2 Sensor 1)". Which sucks because even though it PASSED the tailpipe test I have the headache of fixing the damned thing in order to get my smog certificate. |
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Could this be a code from an occurrence some time in the past? Or did they clear the codes before running the test? Not all shops know what they're doing. I once had to take mine in with the shop manual and a partially disassembled instrument panel to SHOW the guy that what he thought was a missing indicator wasn't even SUPPOSED to be there |
Okay, a heater failure code is usually the O2 itself, so I think you're on the right track. |
I'm hoping so. How do I clear the codes once I change the oxygen sensor? Disconnect the battery for 15 minutes or so? |
I'm not sure what OBD series your vehicle has. All OBDII short term failure codes will clear automatically after the failure is fixed. Some of these failure codes, depending on severity, are stored in long term memory. I believe that O2 failures are one of those codes. Long term codes will also clear themselves automatically if a pre-programmed number of "drive cycles" have occured. This could take days or weeks depending on the vehicle and also how you use your vehicle. You can also purchase several OBDII code readers that have the capability to instantly reset the short term DTC's, however the long term DTC's will have to reset themselves - assuming the failure cause has been corrected. ETA: Disconnecting the battery may or may not clear the short term failure codes (these are the codes that usually set off your "check engine" light). But it really doesn't matter, if the problem still exists the computer will immediately throw the code again. Any long term failure codes will not be reset by a battery disconnect and will still be reported by an OBD read. Disclaimer: I'm not an automotive diagnostician - however I did stay in a Holiday Inn last night.  |