Hn63Anthony

Thanks. I'll try that 👍

Thanks for the thoughts. 90% of my driving is motorway (around 15 miles each way three times a week), so it's running around 70mph and I am fairly aggressive on acceleration. It's a manual and its had all the services at intervals. I'll check the air filter just in case something is blocked. It might be a time for an upgrade to a Mk 4.

With the labour and cost of the OEM pre-cat sensor (£230), plus the diagnostics the total last time was £400 plus vat. Hoping the failed sensor can be returned and I might get some ££ back if it's faulty. Issue I'm facing is what caused the failure if the sensor has failed and hasn't been affected by something in the engine. I've heard these engines don't like E10 and I should use E5.

Checked back with the garage that fitted the sensor, and it was a OEM item and only has a 12 month warranty. I can't believe that these can fail so quickly.

My MK3 Octavia 1.4TSi with 84K miles has failed the MOT emissions for the 4th year running. First year it passed after a good clean of the sensors, 2nd year the pre-cat sensor was changed, 3rd year the engine management settings were corrected, and thi year it's failed again. Serviced every year, no running or power issues, use Shell e10 fuel. I need to avoid another £400+ bill for sensor replacement. Any ideas on what might be causing the failure? Is it the e10 fuel? Thanks in advance.