Hi guys, my mk1 octy vrs (225 bhp) has failed it's last 3 mot's because of it's emissions which are currently ; co 1.350

hc 150 & lamba 970, the car has had a new cat new front and back lamba  sensors ,fluid temp sensor, thermostat, fluid systems flush, new antifreeze/coolant.

I was wandering if anyone else has had similar experience with their car and what they found they cure to be as I don't want to spend a fortune in labour costs with the garage trying out dozens of possibilities before they find the right answer.

Thanks in anticipation of any help you may give me

Ian

 

How have you got it through the MOT?

How have you got it through the MOT?

  soz!

You need to get it plugged in to VCDS & look at the engine measuring blocks to see what the sensors are telling the ECU. That should help to pin it down.

Were the sensors you replaced genuine VAG parts?

You need to get it plugged in to VCDS & look at the engine measuring blocks to see what the sensors are telling the ECU. That should help to pin it down.

Were the sensors you replaced genuine VAG parts?

Hi Paul, yes the parts I replaced were genuine VAG, there are no faults showing on a computer check now so it will be down to a mixture of physically checking each possible cause as well as continuous diagnostics at the same time and gradually eliminating each possible cause as we go.

Thanks for getting in touch with me.

Ian

You cannot rely on fault codes for diagnosing the problem as there are several engine sensors that can be faulty without the ECU throwing a fault code. As I said you need to get into VCDS engine measuring blocks to see what the sensors are doing..

Mine was CTS, that gave me a fail last year.

 

No faults showing, only VCDS gave me the readings which was ECU temp 20c below.

Edited 29 April, 201511 yr by mluton

You cannot rely on fault codes for diagnosing the problem as there are several engine sensors that can be faulty without the ECU throwing a fault code. As I said you need to get into VCDS engine measuring blocks to see what the sensors are doing..

Ok Paul I take on board what you are saying and I will check around for someone who can do this locally. Thanks for the info.

Ian