Be interested to know how much the repair cost Andy ? As I may have a similar problem in the future on my RAV 4 petrol.

Remembering SLO having a similar problem on his 09 Avensis and ending up with a large bill to replace the catalytic converter.

Initially my local dealership blindly quoted (i.e. via email, before checking to see what actually was the problem) me for a replacement lambda sensor (£260 incl. fitting and VAT), but also for a replacement CAT and sundries (£1330 incl. fitting and VAT).

After the car had been checked over, they found it wasn't the one attached to the CAT but the one attached to the exhaust manifold. If removing the sensor strips the threads of the housing, then the manifold would need replacing at a cost of around £1470 incl. fitting and VAT.

Total cost for the latter being ~£1730 rather than ~£1590 if the other sensor was at fault and had the same removal issue. I just have to hope that removing the existing sensor doesn't strip the threads and the dealer is honest in this regard, especially given how many years of loyal custom I've given them.

Given a potentially big bill would result from difficulty in removing such seemingly reasonably accessible parts, I would've thought that any reasonable manufacturer would have recommended they be periodically removed in the car's general maintenance cycle, the sensor and threads cleaned and refitted, with a nice amount of anti-seize (which the new sensors seem to come with).

Similarly with cars with hydraulic power steering and keeping such systems clean and thus keeping the (expensive) system in good order for much longer. No such checks - other than checking the colour of the fluid (and even then, they only do something [separately to the service] if its in REALLY bad condition) - is part of my car's maintenance schedule like with, say, brake fluid.

All it would take is the removal of the fluid every few years, add in a special (but inexpensive - £20) cleaning fluid, let it do its work (including driving using it for a while) and replacing with fresh hydraulic fluid (also cheap).

Total extra cost including labour probably about £90, probably every 5 years / 40-60,000 miles or when needed. I never knew it needed checking until my PS started to get heavier. Far cheaper than replacing the pump (£750 + fitting and VAT).

Edited by Engineer Andy on 30/11/2023 at 14:25