CEL p0456 code, jerking when braking

[RedNWhite]

I have a 2013 automatic FRS, 27k miles. My check engine light came on yesterday. I brought the car to a shop to read the codes:
-p0456 - Current: generic evaporative emission system
-p0456 - generic - pending

I checked the gas cap to see if this is what could have caused it, and it was loose. I tightened it up, ordered an obd2 reader so I can reset the code and monitor the car to see if the code comes back. Today I noticed that the car is jerking every time I slow down for a light/stop sign.

I'm reading through the manual and trying to figure out what to do next. Here are a couple of issues that could possibly be the cause:
1. Low battery, I need to change the battery within the next few months (Edit: I had the car checked before I purchased the vehicle, and was informed that I will need to replace the battery around August of this year)
2. Coolant: I added distilled water to the engine last week since it was at low, I see that it is down to 'low' again

Has anyone else experienced this?

P.S. i'm a newbie, be nice

[humfrz]

Welp, first off, I'd suggest to test (or have tested) the battery/alternator to see if its up to speed. This can easily be done with a simple voltmeter.

http://www.aa1car.com/library/battery_runs_down.htm

If the battery is weak, I suggest you check the water level in the battery (see the drivers manual).

If the electrolytic (water) level is up to where it should be and the battery isn't holding sufficient voltage ....... I'd suggest you replace the battery NOW ...... don't wait till it leaves you stranded.

As far as the coolant level, if your checking it the same way (engine temperature) every time and it continues to "use" any significant amount of coolant, I would start looking for a leak, like around the coolant hoses or radiator.

The "jerky" running may be the aftermath of the evap leak. I'd give it a few starts (days) to see if it will right itself.


humfrz

[guybo]

Welp, first off, I'd suggest to test (or have tested) the battery/alternator to see if its up to speed. This can easily be done with a simple voltmeter.

Voltmeter won't tell you much about the battery. A lot of auto parts stores can do an actual battery test which will tell you more than voltage, you need to know CCA and reserve capacity too. If you have AAA they'll come out to you and do a battery & alternator test as well.

I don't see how the Evap system and the battery are linked, but a loose gas cap WILL cause that code. Is that the OEM gas cap or an aftermarket one? Is the gas cap damaged? Fill up the tank like normal with 91+ octane, see if that fixes the Evap codes. DON'T OVERFILL EVER- even one overfill can damage the Evap system- have you ever overfilled? P0456 is usually gas cap or a leak in the Evap system. A cheap aftermarket gas cap can cause it too- believe it or not, the gas cap is no longer just a cap for the gas tank, it's a highly engineered car part that can cause problems if you get a cheap one.

The coolant is more worrying. A 2013 car with 27k on the odo should not use any coolant. You need to find out where that coolant is going. Do you see white smoke when you start up (not a small amount like normal, but a plume)? Do you smell burning coolant or have you found any on your driveway or inside the car on the floor? Check your oil and smell the dipstick, is the oil emulsified or smell sweet like coolant? Make sure the radiator cap is on tight.

That said, it's also possible that it got low over time (3 years, you can lose a little coolant) and when you filled it up, what you added to the reservoir got sucked into the cooling system and you didn't lose any from last week. Add more and watch it.

[RedNWhite]

Do you think that the battery could be linked to the jerking though? I know for sure that the battery is weak and should be changed soon.

Regarding the gas cap, it's OEM and it has not been replaced. Right now the tank is about 90% full. Are you recommending that I fill the 10% that is empty and see if it fixes the issue after driving for a few days?

For the coolant, I added distilled water to the engine this morning. I have not driven it today, so later on I will check to make sure it's at the same level as i filled it this morning, drive it a little bit and check again, also monitoring it during the next few days.

Thanks for the advice guys, greatly appreciated.

[humfrz]

Originally Posted by guybo

Voltmeter won't tell you much about the battery. A lot of auto parts stores can do an actual battery test which will tell you more than voltage, you need to know CCA and reserve capacity too. If you have AAA they'll come out to you and do a battery & alternator test as well.........

Oh, I disagree, a voltmeter can give an indication of battery health and can indicate whether or not an alternator is charging.

Granted, not as good as a "load test" ....... but better than waiting till your late for work and the car won't start ......


humfrz

[guybo]

90%? Nah, let it be. The jerking isn't related to the battery. I'm leaning towards an evap system problem.

[RedNWhite]

Update:
I added a minor amount of distilled water to the engine (not sure if this could've been related to the problem). Monitored the car over a day, the coolant has not gone down. The car stopped jerking, and the check engine light came off by itself. I also forgot to mention that the quality of the gas that I put in the car could not have been that great (family owned gas station), so i'm thinking that the code and jerking came from the lower fuel quality, or air getting into the fuel since the cap wasn't tightly secured.

Thanks for all the help! Hopefully this issue will not arise again. If it does, I will update the thread.

[Simplisticx3]

The jerking is your car going into limp mode due to the check engine light relating to the evap system. It should go away when that issue is resolved.