[s-cars] Failing the e-test?

[Brent Henry]

I live in Ontario and here we have to do an emissions test every 2 years.  This year, my car has failed the test.  Initially, I just took the car in thinking that it seemed to be running well, fuel consumption was normal, not burning any oil and the power curve seemed normal?

However, on the first test it failed on the Idle test for Hydro Carbons -- approximately 50% higher then the limit.  So I have heard that cars test better if you take them for a long highway run before the test... so I took it out for a 40 minute highway run... it was good and hot, then I took it right into the e-test facility and they took it in 5 minutes later.  It tested considerably better, but still failed!  This time only about 20% above the limit.

So I called my mechanic and he said he had a sure fire way of passing those e-tests... he said to change spark plugs, change the oil, replace the air filter and then put in a liter of Methol Hydrate into a tank of Sunoco Ultra 94 gas.  He said if nothing else is wrong, then it should pass with flying colours!

Well I did all of that and it failed with even a lower Hydro Carbon reading at Idle, then the first test!  So now I am not sure what to?  The only other thing that I can think of is to change the Oxygen Sensor.  I had this sensor changed the last time I had an e-test 2 years ago.  It is one of those Bosch 31913 units that was spliced in (half the price of a sensor with the correct connector). 

I have run the VAG-COM and it does not kickout any Fault codes?  So does anyone have any ideas on how to diagnose this problem?

Thanks,
Brent.