what can i do to prepare a car for emissions testing in which hydrocarbon and carbon monoxide levels are measured during idle and at 2,500 rpm for 30 seconds.

on a 1988 acura legend ls 6cyl.

 

Check your spark plugs, (gap, fouling, connections, wires, etc) possibly run some fuel system cleaner through it. If its burning oil it probably needs rebuilt. Is your catalytic converter in good shape? That should help some. make sure your air filter is relatively clean as well.

 

Make sure the car is thoroughly warmed up before testing.

Leaner mixture (slightly) and more-advanced spark timing will lower those, but it'll raise your NOx levels. It's a delicate balancing act between failing on NOx vs. failing on HC.

 

thanks.

jimblake thought you had left, thanks for the info.

i will make sure to change the plugs/wires before it goes in as well as do an oil change, change out the air filter and make sure its warmed up thoroughly.

the emissions test says:

Basic Emissions Test
The Basic Emissions Test is a two-speed idle test that analyzes emissions for hydrocarbon and carbon monoxide levels. The vehicle is placed in neutral and idles for 30 seconds. After that, it is taken to 2500 revolutions per minute for 30 seconds, and then idles for another 30 seconds.

 

...

 

..