How the EVAP System Works

Here's how the evaporative emissions and fuel system work on your car.
The EVAP system is responsible for venting harmful gasoline vapours from the gas tank into the atmosphere, causing smog.
It consists of the gas tank, filler neck, cap, vacuum lines, switching valves and the charcoal canister.
When the tank is being refuelled, the fill check valve is opened to vent building fumes in the tank to the charcoal canister. The charcoal absorbs the vapour, and will release it into the engine through the purge valve so it can get burned.
When the tank is full, the fill check valve has a float that rises and cuts off the vent line through a diaphragm. This prevents liquid fuel from entering the charcoal canister.
The vacuum switching valve allows the ECU to pull and hold a vacuum on the evap system for self diagnostic. Using the vapour pressure sensor, it can determine if there are leaks and throw a check engine light.
These self diagnostics are part of every car with OBD2, and are essential for an emission test to pass.
The fuel tank is also cut open, exposing the baffles inside, as well as the high and low points of the tank and inlet check valve.
Vacuum lines in between the gas tank, charcoal canister and air filter ensure air is directed for proper venting, purging and self diagnostic.
Care must be taken when working on the fuel system, as gasoline vapours are extremely flammable.

[@gacha24]

This is what I call quality content, very thorough yet concise video and not boring unlike many others

[@speedkar99]

+gacho thanks I'm glad you appreciate my work

[@m4rvinmartian]

speedkar99 And no horrible music. Or in my case, great music that everyone complains about in the comments, because they are old.

[@SugarySnackMan]

You are the best at getting to the point. There are many channels that I wish would hire you! No silly intro graphics or music, just straight and to the point. Even if everything you said was a lie (I know enough about cars to know that's not true) you would still be one of my favorite youtubers. Excellent work once again.

[@decem_unosquattro9538]

I agree a large percentage of Canadians and North Americans fuck around with so much fluff, bs, stupid music that is louder than the presenters voice (a rookie mistake) and meaningless nonsense that it negates the reason why you would watch it. 😂 I don't want to listen to an obstacle course of jumps, rings of fire, and other superflous shit. Anyway - Thank you sir for this video although maybe not perfect it cuts straight to the chase with out the bs intro, plugs, links, ads, and idiotic crap. I know it's not an easy task to create videos and you've done a pretty good job at explaining EVAP SYSTEMS. 👏🏻 9:45

[@viciousocean]

is amazing how much engineering goes behind every single part of a vehicle!!!

[@speedkar99]

+viciousocean it sure is, I love learning something new every time I open something.

[@ben2687]

For sure. Given this, and the amount of knowledge required to be a good mechanic, it's amazing to me that mechanics don't make more money. I say this as a mechanic. Gone are the days of "grease monkeys" working on simple designs.

[@THEGAMINGHELP101]

It's amazing how cars go 200k miles with only a few things failing

[@THEGAMINGHELP101]

@@ben2687 A truly good mechanic that actually knows how to diagnose problems and understands cars very well is rare and most people would not be willing to pay $200/hr for an expert when they can take they're car to the next mechanic that will just start swapping parts for $100/hr.

[@blackmanops3749]

What's more amazing is how much of it is absolutely unnecessary - like the entire evap system.

[@starguy9]

1:15 Searched for hours to find out what these hoses do and you explained it in 30 seconds. Man, I can't thank you enough.

[@speedkar99]

+starguy9 I'm glad you learned something!

[@joshuajohansen229]

This was the best informative KZbin video ever! No B.S. , just a fast, moderately in depth dive into the topic at hand with a real life tare down. Love it! Thank you , it answered my question and I learned a lot. Keep up the good work!

[@speedkar99]

Glad you learned something new

[@maxcohen13]

The content is solid, the pace is quick (but not too quick), and there is no superfluous language or stumbling words filling the air. This may be the greatest example of how an instructional video on KZbin should be done. Well done, sir.

[@speedkar99]

Thanks I'm glad you appreciate my videos!

[@Pwaak]

Pictures and drawings are helpful...but...what you did is an excellent visual of the components and system! Thanks!

[@speedkar99]

Your welcome, glad you learned something

[@yrot1123]

Mechanical Engineering 101 certificate for anyone who had completed watching the video.. Excellent descriptions of the functionalities and reverse engineering of the Evap system. Thank you!!!

[@speedkar99]

You are welcome. Glad you appreciate my content

[@charlsseal7273]

2 12mm of rust. Lol.

[@speedkar99]

+charls seal haha yea this car was rusty!!!

[@Azbikerboy]

"...held on by two 12mm pieces of rust". You made me spew my coffee. Well played!

[@BeardedFordTech]

Lol. It's held on by these 6 points of rust. I love these videos

[@speedkar99]

+Twist_the_wrist83 ugh this car was too Rusty. Darn winter salt on the roads

[@TheNomoPhobia]

This is great!!! I hate bothering my brothers every time my check engine light comes on... stumbled upon your fine work while searching an evap system leak code. 😂😂 I love it!

[@speedkar99]

Glad you enjoyed it

[@sreginkc]

Very in-depth description with visuals. The cut-open visuals make this tech school-worthy. Nicely done, sir!

[@dirkZigander]

Excellent through, concise, fast presentation... The best I have ever found

[@boxbreakracing]

Thanks for showing the real thing in all your videos as supposed to just a diagram. It really makes it much easier to understand when you’re seeing the real parts come of an actual car!!

[@speedkar99]

That's what I love seeing...the practical side of things by taking them apart

[@rosen9425]

Damn, a bit complicated system just for catching vapor. Nice straight shooting video!

[@speedkar99]

+Addictive_LiquoriCe your right. And it's self diagnostics is another nightmare to deal with when things get old and Rusty.

[@guledmah5872]

You explain so quickly that some people feel difficult to keep up with you

[@blackflames786]

Always glad to see a new video from you. Top quality as always. You should do the ignition system and the trick where spark plug porcelain can break the glass on windows and windshields.

[@speedkar99]

Thank you for the compliments, and yes Ignition system is on the list of things to film!

[@PatrickG4531]

Thousands of people are equally frustrated by P0440 thru P0459 codes. They could eventually drive a person to rip it all out and cut it all open just like that. The narration was great. I would be saying stuff like "There is nothing wrong with you, why do you keep throwing codes?!?" Good video.

[@speedkar99]

Thanks. You are right...those codes can get annoying but having a good understanding of the system definitely irons things out

[@ralphnabozny8494]

my old high school buddys are probably watching . we all struggled with cars for the last 40 years. after a while it was a right of passage. you've been busy in the garage after dark too , I bet.

[@speedkar99]

Garage...eh...more like on the driveway...I've even filmed a few videos out in the dark too

[@poxtrue]

Damn !!! Every word is a lesson. We should have more like you teaching at Colleges

[@carlosriosoxnard805]

Wow my boi ... u really spit that. Due to your clear and concise presentation I was able to absorb all this like a sponge.

[@speedkar99]

Glad you learned something

[@eldondedon7884]

I someone walked into a vehicle evap autopsy . Amazing Job Explaining The inner workings. 👏

[@mmmyyy4714]

very good presentation, short, quick and easy to follow. Thanks.

[@colinlyne1660]

I mean you have helped me diagnose the problem brilliant sos didnt make myself very clear cheers Colin

[@EHKOS]

This helped me learn the basics of what an EVAP system is despite my crippling ADD. Thank you!

[@speedkar99]

Glad you learned something new

[@-g.k.4389]

This was awesome you answered all my questions without me even asking them.

[@JoshSchick]

Great video, well done! Straightforward and complete.

[@TheCoatneyadkins]

my new favorite car channel... wish I would've found this channel back when I was in tech school , would've livened up my studies lol

[@speedkar99]

+TheCoatneyadkins haha thanks. I'm glad you enjoyed it.

[@jimstelljes3925]

Excellent visual and explanation of the evap emissions and fuel systems. Thanks for going to the time and labor to explain to us.

[@speedkar99]

You are welcome

[@steveconner6126]

Excellent video. Very thorough and clearly explained. Thank you for this.

[@speedkar99]

+Steve Conner your welcome!

[@scubbarookie]

Very detailed and with great humor! Awesome!

[@csjr9]

Man I love seeing when someone masters their craft. Appreciate the vid Speddkar99!

[@speedkar99]

Appreciate your feedback

[@pirihern9329]

Great video covered everything muchas gracias

[@maldonadolemus]

the best tutorial, talking about evap system I have ever seen. This is educational.

[@speedkar99]

Thanks I'm glad you found it helpful to learn

[@colinlyne1660]

I found your videos really helpful as I have a no start condition on my granddaughters Agila GM UK car. it seems Im not getting a signal to the evap solennoid I think because of your videos helping me. Thanks very very much. I really like how you chop these parts open so we can see how they actually function. Terific fantastic Ill be whatching all of yours videos

[@speedkar99]

+colin Lyne I'm glad it helped and you've learned something!

[@deespasojevic3013]

The car guy I trust to explain how stuff works! Speedkar 💪

[@speedkar99]

Awesome

[@LetsTalkShop]

Thanks man! You made it really easy to understand the parts and hoses that otherwise seem like a mystery.

[@speedkar99]

You are welcome. I was just as confused as you before I tore this down

[@jeffmcmahon615]

Excellent video brother!

[@imnotdon3765]

Excellent explanation! Quick, concise and informative

[@speedkar99]

Thanks

[@mfsperring]

Stellar explanation my friend. Subbed.

[@danielmata1646]

Good job on this video man, explained everything so well, helped me understand why I'm getting a p0457.

[@speedkar99]

Glad it helped. EVAP is certainly something interesting to wrap your head around!!

[@AirplaneFreak]

This video really help me with hose routing on the charcoal canister. Thanks man! It's pretty much the same in the video except mine is a 1998 which has 1 less hose on the canister.

[@cabir3378]

Never heard about this system before thanks for your valuable information......

[@speedkar99]

Your welcome

[@timbarker5663]

Thank you. Trouble shooting and fixing my EVAP. This helped a TON!!!

[@suite42]

Excellent! 10/10 - much appreciated!! Keep up the great work!

[@speedkar99]

You are welcome

[@ScottSchmiedeknecht-rq1jb]

A very thorough video excellent

[@rxs1907]

You are the most understanding and easy to listen to Master of mechanics. Thank you

[@speedkar99]

You are welcome

[@CHIBA280CRV]

Sir you have the best visual and audio explanation of everything on KZbin, thanks for sharing your videos with us 👍👍👍👍👍🙏

[@jmk54]

EXCEPTIONAL rundown clarifying a Toyota EVAP system. Great job!😀

[@speedkar99]

Thanks 👍

[@johnmcadden3404]

Excellent vid man! 👍

[@speedkar99]

+John Mcadden thank you

[@NEVA_STILL]

Great video

[@BMags1]

Fantastic video, super educational and informative. Thank you!

[@speedkar99]

You are welcome. Short and informative is how all videos should be!

[@dborg56]

Awesome video

[@rogerdodger9855]

That pointer tool is superb!

[@speedkar99]

It works great

[@laneburgess1643]

Excellent car autopsy. Keep up the excellent work.

[@speedkar99]

+Lane Burgess thanks, feel free to check my other videos where I cut other things apart

[@Fred-F4]

very informative, thanks

[@mechanic4life526]

You are really good at it very interesting watching your videos keep it up bud.

[@arielmontoya6774]

This guy is so knowledgeable ... Much respect and if mechanics don't work out you could always be a comedian lol ... Tnx man

[@speedkar99]

Thanks for the compliment. I prefer to stick with cars haha

[@CrazyHHO19]

one of the most informative video on evap system well done mate very impressed by your knowledge

[@speedkar99]

+CrazyHHO19 thanks Your right there isn't much out there on evap

[@alanwells4744]

Really informative. Such a good video.

[@amyepperly6944]

I love how u do videos!! Very informative. Thorough. And funny!! Verry susinct!

[@mikepasquini7015]

GREAT VIDEO

[@lexpro2239]

Quality video, thanks for walking us through this

[@speedkar99]

Glad you enjoyed it

[@doodlecharmz]

My Golf had a recall and needed all this stuff replaced, interesting video, very informative

[@ManCaveStudio]

great video!

[@binarymercenary]

Maaaaaan, THANK YOU! Saved me a lot of trouble. Great teacher and funny too. Cheers!

[@speedkar99]

I'm glad it saved you and you were entertained 🤣

[@zerovandez]

Thanks for taking the time to rip stuff up!

[@speedkar99]

Your welcome

[@huskers2b1]

Very helpful , thanks

[@blittlej]

Your videos are always awesome!

[@speedkar99]

Thanks. Look forward to more

[@seshachary5580]

very educative. Thank you Regards

[@iritantNL]

Awesome to see you got another sub!

[@spanmarx]

beautiful illustrations

[@speedkar99]

Thanks

[@davidessien5465]

I love your video so much! This is exactly what I was looking for.

[@speedkar99]

Awesome!!

[@werquantum]

That was an amazing explanation. You’re a great teacher.

[@speedkar99]

Thanks! One day I'll have my own school...

[@werquantum]

speedkar99 Start making a plan today.

[@spencerhill5353]

I could watch this all day haha Best way to learn

[@speedkar99]

Yep that's the fundamentals of my channel

[@tmph1814]

Great video and explanation 👍👏🙏🏼

[@speedkar99]

Thanks

[@arisafghanzada]

Good stuff man, nice show n' tell

[@Copperdee]

love your humour, man!

[@Alex-ti3uf]

Cool, great job 👍

[@Legozahar1]

I love these videos! keep it up!

[@mrflamewars]

Man your videos are always great.

[@speedkar99]

+John thanks !

[@pter81]

Thanks for the video. Highly informative and educational.

[@speedkar99]

Glad you liked it. Thanks

[@edh1689]

Wow the most informative video I've ever seen

[@jeffmyers1167]

very informative Have always enjoyed your videos. well done!

[@speedkar99]

+Jeff Myers thanks

[@kennydude7971]

Great channel

[@SohilShah_Melodyman]

Very informative! Thank you!

[@speedkar99]

+Sohil Shah thanks

[@ghaa4044]

My fav. Channle You r great buddy Best wishes

[@jpuff911]

Very informative. Thanks 👍🏽

[@speedkar99]

You are welcome

[@MarreroBuilt]

Thank you for the very informative quality video.

[@speedkar99]

You are welcome

[@cobrar5161]

informative video.thanks.

[@rosemarcaida8646]

Thank you Sir for information....⭐️⭐️⭐️⭐️⭐️

[@jinsonantony9900]

Nice demonstration

[@speedkar99]

Thanks

[@Hector-rg1bs]

Nice video !! thanks dude.

[@speedkar99]

+Hector your welcome

[@tanveernaeem1157]

Excellent video to decipher mystery of the EVAP system. Thank you for the great presentation. I only wish that the pace would have been a bit slower. I had to stop and replay the clip numerous times to properly understand the content; however your name explains it all.

[@bellinghammond]

awesome. subscribed.

[@aminullahfaizy6154]

Thanks you for all your awesome explanation you are the best sir

[@speedkar99]

Your welcome

[@quangloc4886]

Very impressive sir !!!

[@speedkar99]

+Quang Lộc Lưu Lâm thanks Quang

[@funcars_]

excellent video of demonstration! 👌👌💯💯

[@speedkar99]

+Bryan s13 thanks

[@wilsonaguirregomez3751]

Great video!! Thanks

[@speedkar99]

Your welcome

[@jacquesunu]

You are the best teacher.

[@speedkar99]

Thanks