besides oil change any and premium gas..........any suggestions??? car has 90kilometres

 

Had to read up on the Canadian Emissions Test, and I don't think an oil change(unless you're due for one), and a change of gasoline grades will affect the outcome in any measurable way.

What you need to do is make sure you have a clean air filter, because a dirty one can choke the engine and cause it to run to the rich side. 90,000km is near enough to 56,000miles so you're not really "due" for a spark plug change, that's called for at 100,000 miles/160,000km or thereabouts, but you can always wind in a new set of the proper AC Delco Iridium plugs if you wish.

Check your gas cap condition and replace it if the o-ring is cracked or becoming brittle, and just generally check over the condition of the vehicle, like are there any leaks in the exhaust etc.

As a bit of insurance to avoid any possible "surprises" stop by an auto parts store and have them pull the codes(if there are any even stored), most parts store chains will pull your codes for free.

Your HHR is still youthful at 90,000km so I wouldn't worry unduly.

 

The most important thing is to go for a good drive on the highway and get them to do the test before it cools down. You should call ahead to make sure.

 

X 2, make sure you're up to operating temperature, good catch prod!