Emissions.. trying to find a needle in a haystack

@minimax
regarding reading up about it. I have been doing it for the past month or so, but cannot find the answer, at least for this specific case.

I know that the post cat sensor should be reading around 0.5v, so my value indicate the the engine is running ritch. This is easy info to find. I got the same answer form MOT results. but my question with that post was to see if anyone saw these fluctionions with post cat sensor. I cannot figure out the reason why it would fluctuate until i turn the car off and on again, where it would go back to 0.85v. From my understanting and reading it should not do that.

@David Aiketgate
where did you get your cat?


Anyone had any luck with Klarius cats? Now I found this one, which states that it is approved, so maybe it would work as well
Klarius Catalytic Converter Catalyst Cat 311774 - BRAND NEW - 5 YEAR WARRANTY Completed

The engine starts. The post cat sensor shows it is rich. You rev the engine. The cat saturates and stops working. The first sensor and the second now match each other.

The sensor sends the correct signal (0,8V)when the engine is started. Your reading will have told you that.

@David Aiketgate
where did you get your cat?

I actually got my oem cat from MG obsession, but it was a number of years ago.