driven905

So i went the second year since i have my car for the etest and the results are as follows:

Sept 05 2007 (Last Year)
HC: 9 @ 40kph, 8 @ idle
CO: 0.09 @ 40kph, 0.01 @ idle
NO: 27 @ 40kph
Dilution: 14.59 @ 40kph, 14.11 @ idle

Aug 29 2008 (This Year)
HC: 12 @ 40kph, 12 @ idle
CO: 0.05 @ 40kph, 0.01 @ idle
NO: 17 @ 40kph
Dilution: 14.65 @ 40kph, 13.61 @ idle

Car is a 99 EK stock D16Y7

It looks like there are some differences between the two tests and i was wondering if this shows engine wear? I do the oil changes regularly and replaced the spark plugs once so far. I use full synthetic oil and NGK Spark Plugs.

It shows that the HC went up from last year and that the CO and NO went down. Does anyone know what that means? And what does Dilution mean?

Should i be concerned about these results compared with the last year ones?

Thanks!

sol_searchin

no you shouldnt be concerned there all fairly within spec of each other

driven905

I know the variation is minimal, but i would like more information on what the values mean and what affects them.

chris_v2

For a more thorough explaination, google is your friend.

NOx is basically hot exhaust temperature

HC is unburnt fuel

CO is an insufficient burn, lack of oxygen, too much fuel.

You'll never get the same reading, even if you test the car right after a test. Coolant temperatures are different, ambient air could be different. In your case, since a year has gone by, your o2 could be a bit more lazy, your cat could be clogged up a bit more, dirty fuel injectors, etc.

driven905

i did Google ... and i know what the acronyms mean.

i couldn't find much information on it as to what the values mean ... and i already know the max limits off the E-Test.

I was interested to know if its possible to determine if the car is running rich or lean, is it more inefficient now, and so on ... and also what does the Dilution value mean?