PaulC5 wrote: 11 Oct 2025, 13:42
Where did you get the new sensor from and what make is it ? What is the engine temperature with these readings ? Was there a fault with the old sensor that made you want to change it, was its connection bunged up with oil/carbon ? If you put the old one back do all the other readings differ ?
The lambda values seem a bit odd, if the downstream one is the same as upstream it suggests the catalyst is not doing anything. The upstream one ought to be switching constantly and not be steady unless the engine has just been started and is still cold. Do you have any fault codes stored ?
Just a cheapie Aliexpress unlabled sensor, bought on the basis that either ir works and shows reasonably realistic numbers in Diagbox or it doesn't and I return it.
Engine was up to temperature but not run for too long so not excessively warm.
Old sensor may not have been faulty but changed as a matter of course to see if it makes any difference to an slight hesitation on overrun ongoing issue.
Connector was fine, I had cleaned that previously.
Haven't tried replacing the old sensor yet, waitingh for a few comments first.
No relevent fault codes. ECU did throw a P1153, throttle position sensor, error after resetting the ECU by disconnecting the battery overnight but cured that by the throtle calibration procedure.
