I have had a lot of issues with my recently purchased S60r, most of them I have slowly but surely solved but there is one issue that is proven to be very difficult.
The car failed the annual mandatory testings because of poor emissions. The car has a too high CO content, and it varies during the measurement. For a few seconds it is fine and then it will suddenly sky-rocket to way over allowed values.
See video below:
The following is done to the car recently:
Full oil service
New spark plugs
TME catalytic converter and exhaust
New do88 intercooler and piping
New front and rear lambda sensors
New IAT and MAP sensor.
MTE stage 2 software.
Car runs great, no fault codes for engine and MTE logged the car when software was uploaded and we did some full throttle pulls. Everything looked good.
Idle is fine, full throttle is also fine.
I just cannot understand why I would get high CO?
I have logged lambda, MAF etc. I do get oscillations on these values and fuel trims also vary up an down a few percent. But I think this is normal and deliberately done by control system to always work around lambda = 1 and get the cat working as it should. See pictures and video below.
First I thought maybe wideband o2 sensor was bad because switching on the narrowband did not match with readings of the wideband. But I changed wideband to a brand new one and no change.
The only thing I notice is that the car smells a bit bad from the exhaust. It is not a smell I have had from any of my other cars.
What should I try next?
New PCV system? (I did the glove trick but this does not show over pressure) New injectors?
Any ideas are welcome!