Having problems with your 1996 Chevrolet Blazer ?
Service engine soon. scan code p0440 - 1996 Chevrolet Blazer
This is an evap small leak code and is most likely caused by the gas cap. The computer and evap pressure sensor determines if the evap system has any leakage and that is why the code is setting. Most Blazers have a plastic strap that is attached to the cap, make sure that the strap is not getting caught under the cap and preventing a good seal. The rubber seal on the cap may also be damaged so check that too. Also when you get gas, over the years the inside of the filler tube gets knocked by the nozzle and that damage could prevent good sealing as well. Other issues with this code could be in the evap system components such as the evap canister, related solenoids, and hoses. This would have to be checked at a shop for you. The first place to check is the gas cap itself and even replace it you suspect it since they are not expensive and you can do this yourself. As stated by one of the other posts, you can leave the battery disconnected to reset the code, but only do this after you fix the problem or as a temp. solution since the code will only return shortly.
Repair Help & Product Troubleshooting for 1996 Chevrolet Blazer
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