Evaporation Control Canister


#1

What is the evaporation control canister, and did I just waste $700 getting it replaced in my 2003 Toyota Corolla? I know nothing about cars, but this repair just took a chunk from my wallet. Was it something that could’ve waited to be fix?


#2

The evap canister is where gas fumes from your tank are stored to be sent to the engine to burn rather than being vented to the atmosphere.

Since no one knows a thing about your car, what it was doing, why the canister was replaced or what the car is now doing, no one can tell you whether you just wasted your money or not.

Could it have waited? Probably. Evap system problems usually don’t cause too much actual trouble. Should it have waited or not been done? Well that depends on whether it actually needed to be replaced or not.


#3

They made cars for about 75 years without them…So yeah, you could have waited until your next emissions test…$700??? Did they have to remove a fender to get to it??


#4

Cig’s right, we don;t have anywhere near enough information to guess. If the charcoal bed was saturated and the gas tank couldn’t breath in, not replacing the canister could have caused premature fuel pump failure also. Sometimes postponing a repair can cause the cost to increase by cauing secondary and tertiary failures.


#5

I cannot speak for the Corolla. My 2002 Sienna had a failure, related to leak-down of the tank during testing, the same one that fails if the cap is leaky. It was very intermittent, and I chose not to spend hundreds of dollars to pay a mechanic to look for a problem that is not failing at the time I take it to the shop. At one point, it went several months without a failure.

Finally, a Sienna owner on the now defunct Sienna Club who had the same problem on one of his two Siennas, swapped parts and it was the Canister Assembly (not simply canister) which fixed it. He said there are low pressure valves in the assembly, and he believes one was sticky.

I took it in, told them to replace without troubleshooting, they had me sign a waiver, that I was taking responsibility for the troubleshooting, I worked as a high tech troubleshooter for over 30 years, so I signed, they replaced, no more problem.

A lot we don’t know. But, if you let the mechanic do the troubleshooting, I can see where the $300 for the canister might become $700. Troubleshooting intermittent problems can be very expensive.