Hi folks!
This is my first post but I've lurked for a while for other issues, so thanks to the amazing community!
I have a 59 plate 1.33 petrol Auris (NRE150) with 103k miles that is giving a check engine light for P2195.
In my haste for a quick fix I took it to an independent garage who "replaced the lambda probe" and gave it the all clear, but the check engine light has come back on.
The diagnostic procedure for this error code is lengthy. The code itself is generated by a prolonged high voltage recorded from the air fuel ratio sensor (B1S1) which is the sensor in the exhaust stream before the catalytic converter (89467B on this diagram), either on its own or in conjunction with the heated oxygen sensor (B1S2), which I believe is the sensor after the catalytic converter.
I can see that the garage has installed a new sensor in B1S1, and testing it with a multimeter gives decent readings. It also seems to respond as expected when the ratio is recorded using an OBD2 adaptor - hovering around the magic 14.7:1 (~3.3V) and jumping up in response to a fuel cut.
I've also tested the resistance of the wiring harness that links B1S1 to the ECS, and tested the vacuum pipes for leaks using the carb cleaner trick to no avail.
What would be your next step? I don't want to spend a fortune on replacing parts to track down the issue! Is it worth replacing B1S2 too? Or do you have any other suggestions for likely culprits?
Thanks for your help!
Ari