I know this is a sensor issue. No codes. The only sensor that may have an unreasonable range, but I wouldn't know, is the upstream o2 sensor, as it permanently reads 2.0 and the voltage doesnt change.

My problem is I don't know what my sensor readings should be, and im relying on not having a code. Does it point to needing a new upstream o2 sensor despite no code and no dpf problems?

Would anyone with answers need the read outs from all the sensors? I can record a forscan live read out if that would help.

2 minutes ago, SquidgyB7421 said:

despite no code and no dpf problems?

What are you using to read the DTC's with ?

The short answer is that if there was a fault with your O2 Sensor there would be a Fault Code as there would be with any emission related Sensor.

The thing to bear in mind is that Diesel Engines and Petrol Engines work differently and your O2 Sensor is likely to be a Wideband one as well so the reading you are getting is highly likely to be correct.

Any information you see on YouTube is likely to be for a Petrol car with an old Narrowband Sensor. 

21 hours ago, unofix said:

What are you using to read the DTC's with ?

Forscan

On 3/31/2025 at 9:41 PM, Tizer said:

The short answer is that if there was a fault with your O2 Sensor there would be a Fault Code as there would be with any emission related Sensor.

The thing to bear in mind is that Diesel Engines and Petrol Engines work differently and your O2 Sensor is likely to be a Wideband one as well so the reading you are getting is highly likely to be correct.

Any information you see on YouTube is likely to be for a Petrol car with an old Narrowband Sensor. 

So if not the o2 sensor, and no codes showing other sensors being at fault, and the values on a live read out looking normal, what would my problem be? Do I need to reset the ECU? How do I resolve the issue?