My 03 ZX2 is starting to drive me crazy. It has set a P0453 code, Evaporative Emission Control System Pressure Sensor High input. I have one of those scan tools which can reset the light but it always comes back. Where is this sensor located at? If anyone out there has seen this problem, any advice would be greatly apreciated.

 

Hello and good day to you:

This sensor is related to the Vapor canister not venting correctly. Are you by chance Filling your gas tank full, and then Topping it off??

The vapor from the fuel tank and fuel system if its is carbonated, has a vapor line . Earliermodels of your car came carburetter, most models are fuel injected. Vapor goes into canister, if there is enough to liquidity, it will then collect in the bottom of the carbon collector. Now that you know how it works, the common failure is the gas cap. Sealed system requires a sealed gas cap. On a warm day after driving a short while, stop turn the car off, and remove the gas cap, it should make a swishing noise, as air enters the tank to replace the fuel you used. They should have checked the gas cap at the smog lab. Replace as needed. If there is no swishing noise, move on to the large line from the tank to the canister, check for cracks. If carburetter, check the line from the carburetor the the canister for cracks. It is uncommon and unlikely that it is the canister itself. Last resort, replace the canister, most junk yards will have a car similar to yours, it will be fairly inexpensive.
Location of this Vapor Canister is either above the Gas Tank, or under the Drivers side Fender.

I hope this helps, good luck.