brettmarl
Regular Contributor
One of my 225-AK3's started throwing a code-1 (retrieved via MIL/paperclip trick), which is bad O2 sensor. I put in a new sensor and it seems fixed. However, I'm curious to understand more about the behavior I was seeing and the cause.
The engine would throw the code about 5 minutes after starting up. Didn't matter if I was just idling or was on plane and rolling along - seemed to be thrown based on a time-since-start. Stopping the engine after the alarm and restarting it - would cause it not to alarm again for the rest of the day. Even after a few hours at dock it would startup again fine and not throw the code. After a few days sitting, it would throw again on startup.
Wondering what would cause the behavior? Maybe the o2 heater circuit was going bad and at some point on restart there is enough engine heat once running to get a good sensor voltage? I was expecting a failed o2 sensor would throw codes more consistently on every start or periodically while underway.
Lots of great code-1 threads here that end in "put in a new sensor and it worked", but haven't seen many that detail the root cause.
The engine would throw the code about 5 minutes after starting up. Didn't matter if I was just idling or was on plane and rolling along - seemed to be thrown based on a time-since-start. Stopping the engine after the alarm and restarting it - would cause it not to alarm again for the rest of the day. Even after a few hours at dock it would startup again fine and not throw the code. After a few days sitting, it would throw again on startup.
Wondering what would cause the behavior? Maybe the o2 heater circuit was going bad and at some point on restart there is enough engine heat once running to get a good sensor voltage? I was expecting a failed o2 sensor would throw codes more consistently on every start or periodically while underway.
Lots of great code-1 threads here that end in "put in a new sensor and it worked", but haven't seen many that detail the root cause.