Apologies, long post. Grateful for a sense check or any advice on the following (with 10 days to go until MOT expiry!) on my 68 plate Octavia Mk3 estate.

Engine warning light lit last week when away on holiday. Few hundred miles drive later and managed to plug into my basic OBD reader and got the following codes:

P220B00 Nox sensor supply voltage bank 1 sensor 2 - circuit passive / abiogenesis

P22A700 Nox sensor heater sense bank 1 sensor 2 - circuit range / performance active / static

28992 - no description found - passive / abiogenesis (rechecking this evening and now active / static)

B200000 - ECU malfunction active / static

Fault codes cleared with OBD reader and didn't recur on restarting ignition but then took a 15 mins country roads drive and on restarting ignition warning light back on and above codes back on rescanning.

Bit of research makes me think my Nox sensor has failed and options are to have it coded out (which I'm less keen on) or replace. I had a look under the car and have noticed my passenger side wheel arch has cracked / split open. Removed the undertray to access the Nox sensor and found it soaking wet so "hopefully" have at least identified the problem (looks like these faults / error codes can be difficult to pin down).

My options for replacement look to be a second hand unit from a popular online auction site (unsure if I'm allowed to name), an OEM module online or a new aftermarket module. OEM modules are significantly more expensive and I'm not sure would arrive in time for MOT (not a disaster but would like to avoid and a little reluctant to spend so much given there could be another issue causing the error codes). I've read aftermarket modules can be variable in quality and at risk of premature failure. I would prefer to get a used module on the online auction but can't find an exact match for part number.

I've uploaded a photo of my module. Most of the online auction items have the same part number but different three letter code after "NO x C4" (mine is SME while the closest one I've found online is SVZ) or generation (the only 'SME' module I've found online is Gen 3.0, mine is Gen 3.6).

Given the above, does anybody know how close a replacement module needs to be to the original? And if some difference is ok, is it better to match 'SME' or module generation? Would a Skoda dealer be able to more easily source a part?

TIA. If nothing else hopefully this is a cautionary tale to repair any undertray / wheel arch damage - I suspect this is an expensive and inconvenient lesson for me.

Update. Replaced with a used module from eBay a couple of days ago, part number the same but other identifiers different, and engine light is off for now! Fingers crossed that's it sorted, now need to fix the wheel arch liner!