2007 BF225 - Slow Alarm Beeps at Idle

Symptoms
A - Slow alarm beep after sitting at idle or slow troll for a few minutes.
B - Huge drop-off in fuel economy. Last week 2.9 - 3.5 MPG, yesterday 1.5 - 1.7.

It's been a couple years since I last remember this happening but from my recollection a slow alarm beep at Idle is indicative of a blown O2 Sensor or possibly a bad connection?

The last time this happened the shop performed the recall update on the exhaust system that was supposed to correct the problem of water/moisture getting into the engine and blowing the O2 sensor.

Sound about right? I'll pull the ECM codes tonight.

Thanks for any inputs.

probably O2 sensor again. beep at idle and no beep at high speed, high fuel consumption. With the new exhaust and new ECM also it is same issue i had faced even too early compare to old stuff. the upgrade is not much effect . check the code and let us know.



wajira

Sounds like you probably diagnosed the problem correctly, but could be something else. When you pull the codes, if you get a single short flash on the MIL light, it could be the HO2 sensor, OR a bad connection, OR a misfiring plug. Before buying and changing the HO2 sensor, pull your plugs and see if they all seem to be burning evenly - light brown color. If all or most are sooty, and the HO2 connection is clean and tight, then it's probably the HO2 sensor itself.