Hi - I really hope somebody can assist with an issue I'm having with my 2007 XC90 3.2l. I've browsed the threads a fair amount and unable to find anybody mentioning the same issue so feel free to redirect me if I've missed it!
A bit of background if it's relevant... I was in the midst of a long drive (just entering North Carolina on a Boston to South Carolina trip!) when my check engine light came on. I stopped by an autozone to see what the code was (P0430 - catalytic converter); considering it wasn't terminal, I pressed on with my journey, and reset the code by disconnecting the battery to see how long it would take to reappear - less than 5 miles later it did come back on. When I arrived in my destination, I took it to a Volvo garage for their diagnostics and the error code was P1157 (Bank 2 Oxygen Sensor) but the catalytic converter error had not returned. I am now looking to get the sensor replaced.
However, following the Volvo garage visit and after driving for a few minutes, a regular ticking noise could be heard coming from the area below the steering wheel (around where the fuse box is). It is a regular pattern that comes every 10 seconds or so and is series of 3 rapid ticks, then 3 ticks slightly slower, then 3 rapid ticks again. Like it's an S-O-S Morse code signal from the car. Is this an audible warning in case you haven't noticed the CEL of if the CEL bulb has gone? or is this something else?

Thanks for your help!!!