EVAP System, is it safe to drive?

I have a van that 2 evap codes caused the check engine light to come on. I got the light turned off but it turned back on. Is it safe to continue driving it with out repairing anything? Will anything happen? Thanks.


Yes, it is safe to drive, but–depending on exactly what is wrong with the evap system–you may have problems fueling the van. In fact, some types of evap system problems can cause gas to come spurting out of the filler when you are fueling the vehicle, so in some cases this could be a safety issue of sorts.

Additionally, if your state has emissions checks as part of a state vehicle inspection, you will be unable to pass the inspection. However, all of these possible problems notwithstanding, you can drive this vehicle safely.

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Its very unlikely to directly cause any problem.

There are a couple of indirect problems. One is that the evap system was designed to keep you from running around venting gas fumes to the atmosphere. Not everyone thinks that’s important. I do.

The second is that if you keep driving around with the engine light on you will miss the next problem that occurs - but the next problem could be a bad one.

Perhaps you could post the two codes along with what you were told about them & get advice on looking at fixing it.

the codes were p0442 and po455.


Yes, it is safe to drive. I know because I did so for many months before finally getting my lazy act together and replacing the defective solenoid. It was as simple as that, an easy DIY fix. Then I was able to have the car inspected.

I don’t advocate postponing the servicing. I’m just letting you know that nothing bad will happen if you can’t get around to it for another few days.


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"the codes were p0442 and po455"

Presumably you have checked your gas cap? Clean the filler neck & the gasket on the gas cap. Smear the gasket with a bit of petroleum jelly or something of that nature, clear the codes, reinstall the cap and see what happens.

Other than that just start hunting for loose/damaged evap line. Given the you have a “gross” leak, it might not be too hard to find.

One more thing, stop filling your gas tank when the handle clicks off the first time, don’t keep adding fuel. Doing this causes liquid fuel to get into the purge valve. Since this just started, if you stop overfueling now, the system will fix itself.

As Keith wrote, Don’t top off the tank. Chances are the car’s owner’s manual and maybe a sticker on the car will warn you not to do that. Now you know why.

A leak, which is what your codes indicate, won;t affect operation of the vehicle.

The problem is that if the light stays lit and something potentially damaging develops, you may not know it because your “early warning system” (the CEL) is effectively disabled.

I have a 2010 ford e350 utility van with the codes P0456 (evap system small leak)
and P1450 (unable to bleed up fuel tank vacuum. The pressure when removing the gas cap I have been driving it for about a week and now it wont start. ???

I have a 2003 Chevy Silverado that throwing evap codes po453 po650 snd po128 is it safe to drive this vehicle until I can get it taken care of

Yes, it’s “safe” to drive it in the short term, but that P0128 code seems to indicate that your engine is running too cold. This can result in increased engine wear and faster deterioration and dilution of the engine’s lubricating oil. If this was my vehicle, I wouldn’t drive it like that for more than a few days.

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If you have a temp gauge you may be able to tell how cool it is running. I had one that was maybe 3 degrees too cool, not as urgent as never warming up, a new thermostat fixed mine.

Typically, a solid check engine light means you can drive it to the shop.

If that light ever flashes, it means you should stop driving immediately until it’s fixed.

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