This is the kind of person that was smart enough to do anything he wanted in life but decided to become a mechanic, therefore a "best of the best" technician/instructor.

EXCELLENT troubleshooting / diagnostic testing !!! Just can’t say enough about this brilliant young man who put all of his diagnoses in laymen’s terms so a not so smart guy like me could comprehend .... lol . Very good ! Thanks so much .... Jack

Very prepared, went smoothly, spoke clearly, and I learned something...Thanks Michael.

Excellent video!! Very clear and precise!! I found a reference to this channel from Eric O. at South Main Auto channel! You should give him a shoutout back! In the system info, the number 12.XX mmHg, is a reference to millimeters of mercury!! Hg is the periodic table of elements symbol for Mercury!! When you measure Vacuum, as in a typical A/C system, it's measured in inches of mercury (in Hg). And a typical cross over measurement would be inches of water, in SAE numbers!! I recently had to do this specific job (private, for a friend)! He was showing a evap performance code. He replaced the purge solenoid, at the behest of the O'youknowwho parts store!! PARTS CANNON ATTEMPT #1. That didn't work, so, he called me for a favor! I came, and immediately tested the vent valve!! It worked, but after two or three tries, it started to work only intermittently! And I showed him my findings!! That it was partially working, it needed to be replaced! The money light returned!! PARTS CANNON ATTEMPT #2. I used the code scanner at the parts house, and noticed that the tank pressure was absolutely following the purge attempts, and the pressure spikes, however, it was working but showed 6 in/Hg as atmospheric!! So, even tho it switched up and down as necessary, it wasn't calibrated correctly!! A quick pop of the fuel cap, proved my points!! But changing the sensor was a bit bad for me!! The truck had been used by the previous owner, to haul mulch!! For a while I'm guessing!! And the mulch ended up on top of the fuel pump area, AND SOLIDIFIED! Half a tank of fuel, no way to disconnect the plugs. Laying on the ground, with jack and stands!! Oh boy what a favor that turned into!! We spent hours chipping out the mess, just to get the tank out!! And then the clean up began!! What a job!! But the tank went back in clean, dry, and empty!! With a new sensor!!

You sir deserve a medal of some sort. This has by far been the most informative video I have watched in the past week. Hundreds. Thank you sir.

Just came back to say this fixed my check engine light with this code. Had I not seen this video I would have change the canister. It really is not easy but it's not impossible. I did it without a lift. Lowered the tank just enough to reach the sensor. Code clear and it's been six months

This was very informative and easy to follow along. Thanks especially for showing the need not to have to drop the gas tank.

Excellent teacher. Well done on diagnosis! I have a p0446 on a 03 suburban. I’ll check the vent line and solenoid for clogs before having to drop the tank since top of suburban tank isn’t accessible unless tank is dropped. Tried a gas cap but of course that wasn’t the issue.

Thanks Mike, This is a refresher for me My next job is a P0446 on a 04 suburban flex fuel. Thanks!

09 Silverado, new ac delco purge valve, new Standard vent control valve, new Gm gas cap. Shop advised to change vent solenoid. Truck sometimes very hard to fill with gas then no problems filling. Vent canister is not plugged. Perplexed. Glad you posted this. I only have a bluedriver but I’m going to check the pressure readings. On live data the pressure fluctuates between -14 to positive while driving.

Great video. It was very professional, informative yet simple. And i loved how you showed the struggle of installing the sensor. I thought you removed the connectors and sensor WAY easier than most. So you are human like the rest of us. Haha

Excellent video. You definitely have what it takes to be a great teacher. Great explanations 😊

As Lord Shaxx would say, this is amazing. Just solved my Chevy Silverado P0446 code that the Stealership said was the vent solenoid. Saved 1K+ 🤙

Outstanding diagnosis, fix, and explanation. Thanks for the lesson!

Degree in electrical engineering and a mechanic! Awesome job! My mechanic has come to the same diagnosis as you!

Awesome video! Wish I came upon this sooner...just a shadetree guy...but this is the first video that really explained why I've been chasing my tail so much with evap codes on my 08 Silverado. Thank you very much!

Excellent case study. I really like your diagnostic approach. Thank you sonics for this class. Looking forward for next one. Cheers.

I need a better scan tool and need to brush up on my troubleshooting on wirer harnesses. My scan tool just kept reading P0446 vent control circuit. This taught me that not everything is as it seems. Kudos to you man, this video helped me fix my problem thank you.

Hey, I'm here for a 05 Express 3500 with a PO449 but thought I'd watch anyway and am very happy I did. I am definitely going to subscribe since this was one of the best "classes" I've ever seen on KZfaq. Thank you very much.

Brother, that is a very well done video my friend. I have an ‘12 GMC Sierra quad cab 5.3L with a tad over 167k & just like my motorcycle n’ things, I keep ‘em in great shape. Just yesterday I got this code, so since I don’t even have a basic diagnostic tool, I had Autozone at least pull up what the code was that caused the check engine light, that bein’ P0446 EVAP. I’ve yet gone to school for auto mechanics, but am an aircraft mechanic in the USCG & am able to hold my own bein’ mechanically inclined. Autozone’s results they printed up said that most ASE certified mechanics have typically replaced those fuel pressure sensors on GM vehicles. Gonna take it to Christian Automotive tomorrow here my state Lonestar state of TX n’ have them pinpoint the discrepancy with a better diagnostic system as you have. Again, thanks for the informative video brother! God Bless, Jason

found you from South main Auto repair, Excellent info on the old gm evap system. Great Work Mike will be back and telling friends.

One of the best how too videos I have ever seen.........

Thank you for the video. I've been trying to figure out what sensor tells the computer there's s problem (pressure, vac, flow, ???). I've tested the EVAC systems individual components; they're working properly. I'll be testing that pressure sensor tonight. Troubleshooting and theory. Great video

Safety when doing the reach around. Using the sharp edge condom tape was genius Mike! This video went down smoother than the delicious India Pale Ale I was drinking while watching. Great job once again, thumbs up.

Informative and professional...not annoying like other quirky videos out there.

Excellent video and that's after just coming off of finishing ScannerDanner Premium's full class lecture playlist course. You're definitely up there with the best of them. I really appreciate Wells supporting this channel like this.

3 years ago I cut a hatch in the bed over the fuel pump location . My tool box sits on top of it anyway. Now that I have to change this sensor what a dream to have the hatch just lift it up change the sensor and done in 15 minutes. The reason I put the hatch in in the first place was because my research told me fuel pumps and this sensors are problematic in 1998 Chevy's and I needed to change the fuel pump at the time and being that I dont have a lift and I'm too old and fat to crawl under and do this from below I figured cutting a hatch w a grinder would pay off some day and today is payday.

Great job Mike. Your excellent understanding of the system and critical thinking along the way sure help you make it look easy. But I was right there with you at every step. You just made a lifetime customer with that truck owner. BTW, love rockin' my wellstech "T" shirt. Thanks Mike and looking forward to your next class. It's Thursday the 13th correct?

My 2003 Colorado the frame rotted out so bad it almost snapped in half . This truck is not too bad but is on its way to rusting in pieces. Good video it is helping me with my 2003 Aurora . At present it is constantly venting so I am assuming it is the vent valve . I was a auto mechanic for years .

I'm learning so much from you! Excellent Teaching!

excellent video. Thank you for all your help.

Great job, nice scan tool to have. Mine started small leak for a few years now Gross leak. GM seems to have different charcoal vapor canisters.Mine has 3 ports. Sites show charcoal gets into the lines. My first thing is to smoke test. 2004 Suburban. Ohm, continuity test purge valve19.4 all good. Will check with 12 volts. You’re too far for my drive. I’m old school, amazing Technology, you explain it well. 👍

They are very tuff to get back in!! I did mine 06 gmc! I:don’t feel like ever doing another!!! 💙✝️

Thank you very much, and for the innovative way to diagnose faults. I am one of your biggest fans, and I have watched all the videos that you uploaded, and I hope that you will continue to upload more scientific videos, You really are a genius engineer I wish you very good luck👍🏼

Mike great work here. I came across your site channel today. Oh yes I have subscribed. I am 60 years old and am amazed at your level of talent and dedication.

Thank you for shining some light. Swapped the actual evap valve. $35 oem part and $100 for mobile tech to drop tank. Code didn't clear. Also asked him to swap fuel pump's float sensor since I run out of gas when gauge says I still have 1/8. So now replace FTP and float lever. (2005 Chevrolet Uplander)

Excellent video. Thank you sir.

Great Video, helped me fix my 03 Silverado, Thank you!

Great diagnosis video. Thanks for taking time.

Thanks for sharing Good video It's good to learn more about Electric car problems Very professional teaching. 🤗🤗

Evap system has been a mystery to me. But with it being the worst offender when it comes to setting up the MIL light I am glad to have come across you alls Chanel I am sponging up all of this info thanks , can't wait to catch up with the rest of them.subscribed!

Excellent presentation!! Well Done! Thanks.

Nice concise clear explanation, ur videos are getting better all the time, anymore colorado videos would be great to see, especially a thermostat change, thanks

Well, I tested my MAP and Fuel Pump connections at the harness and I had voltage being fed to both with key on. 4.9v on the MAP & 14v+ on the Fuel Pump plug. (Grand Prix, 3.8L) My code was cleared and hasn’t returned in several days but it returns sometimes. Could be my Vent Solenoid. Maybe.

Thank you and great video! John 3:16 For God so loved the world that he gave his only begotten Son that whosoever believeth in Him shall not perish but have everlasting life.

the classic reach around Eric O terminology

Great video and tips

Extremely badass vid bro love ur style had my attention throughout the whole thing looking forward to doin this test on my 04' colorado..p0446 just popped up smh..

Thanks so much, informative video.

Nicely explained and made look simple.

on a 2000 impala, charcoal filter is good- the vent clicks and opens. But still fills slow. Maybe pressure silinoid on engine??? OR maybe something on fill hose ( doubt that,) seems like if fill before drive far---will fill with gas pretty well.

Very good video my friend thanks

Excellent lesson. Thank you!,

Again outstanding work so smart maybe now I can fix my chevy aveo code po446

Thank you for this nice and very well explained video ,bravo !

Grasias amigo. Eres un profecional You are very intelligent

Great video mike, that's a trick code,cheers and take care yourself

Great diag/training video. I appreciate the thorough explanations.

in the 07 chevy express 3500 s gm supposedly added a mouse hole so you can access the FTPressure sensor thru a hole in the side of center storage drop down compartment .

Very well explained and your camera work is excellent.

Awesome video my guy keep em coming

Excellent video!!! Thank you very much!!!

Had this code (P0446) on my 2004 Silverado. Turned out to be the fuel pressure sensor. I should have watched this video first. I changed the EVAP Vent solenoid. Check engine light didn't budge. I then changed the purge valve in the top of the engine. Check engine light still on. I had to unbolt the truck bed and lift it partially to get to the fuel pressure sensor. But that did the trick. It's been a few weeks and the check engine light has stayed off. And I was able to pass smog. Hopefully it doesn't come back on.

another great video. crisp clean approach

Awesome video

Might want to grab a cheap endoscopic camera so you can watch where you're going with both hands free. Great video and advice. Thank You

Awesome video. Thank you.

Thanks now if I can explain it to my mechanic he can fix my truck. Randy Bang

Great video Mike with the diagnosing as it just shows that you've got to understand a system if you're going to troubleshoot it. It's pretty obvious that the other shop didn't do any diagnosing and was making a call based on parts failure such as the vent valve. That sure did look like a bear reaching over that edge, but it's better than dropping the tank. Oh, how is the little fella doing and hope the rest of the family is doing well too? Take care Mike...Terry

Thanks for the video. Super job ! I’ve noticed most of the diag videos I’ve seen always include a wiring diagram that you guys just “pull up” . Is there a website or is it one of those $2000 a year subscription things. I’ve always had to go get a vehicle specific manual for whatever I was working on. I don’t do it for a living but I help a lot of people in my community and at work. Keep up the good instructional videos as I am learning a lot. Thanks!

Good stuff

Great video lecture!! I have the same issue on my 2001 isuzu rodeo 3.2 v6 2wd. They replaced the vapor canister and the purge solenoid next to it they performed a smoke test. Also, the purge solenoid in front of the engine plus the 2 vaccum hoses in front of the engine as well. In addition a new fuel pump. But still that pesky check engine light still comes on P0446!!! do you think its the same issue fuel tank pressure sensor? please help? thanks

If it doesnt make the "whoosh" sound, does that mean the vent valve is bad?

I have this check engine code. If I replace this sensor will it also help when I pump gas. Right now my truck is very hard to put gas in keeps clicking off I have to hold the nozzle up in the air to fuel up.

Very informative! Thanks!

Absolutely loved the video. Very clear instructions. I have a 2008 siverado with the same issue and code. Dealership couldn't find it but said the purge valve and solenoid were fine, so its gotta be the pressure sensor right. The video showed that it's possible to test and change it without dropping the tank, although not easily. Is that possible with a 2008? Seemed like a different body in the video

Awesome video real professional.

I have a VUE that has the po446 right now. Sensor constantly reads 4.2v or higher and shows -13.25 h2o at all times. We pulled the tank and ran the tests and everything looked good. Replaced the sensor and right back to stuck at 4.2v. Figured we got a bad sensor, so we ordered an AC Delco. Still showing over 4 volts. I'm a bit confused on this one.

I have an 05 silverado 2500hd 6.0. And started getting the same code. So hopefully it's just the sensor or it could be the evap canister.

Very thorough, Mike you're wizard...just curious once you saw the connectors and determined clip style other than needing a free hand, when you placed flashlight did you realize you pointed it at an area that you were blindly disconnecting by touch only. Actually had a StarWars feel to me, let the force guide you luke..oops Mike. Diag guru. You're awesome 💪👀💪

great class as always

Excellent video!

Awesome, thanks.

Great video, thanks.

Great video man! thank you.

So, I'm having the opposite reading. My tank pressure is reading full vacuum 4.8v -30.63mmHg (-16.41 inH2o). Is this still possibly the tank pressure sensor?

Hi Mike, just a big question for you.. l have p0446(1of2)l already changed the gas tank pressure sensor, vent purge selonoid and evap vent selonoid but l can’t fix the problem. This is the first time it has happened, thanks for help god bless you

excellent presentation. So the pressure sensor was bad?

From this I learned that a bad fuel pressure sensor in the gas tank will damage the entire EVAP system but there is no engine code for it. Purge and vent valves are doing what when the fuel pressure sensor is bad? What is the air flow in the charcoal canister?

Man you just awesome 👍 thanks for the help.

Nice diagnosis Mike as usual. I explain to people a DTC does not mean that part is bad and that $90 dongle they advertise to buy to keep from getting ripped off by mechanics is actually them ripping off unsuspecting buyers. All that $$ we spend on diagnostic tools and all we need is that dongle...crap!

I've changed all sensors in that loop. The new tank pressure sensor actually didn't work lol. Tested the old one and it was spot on yet I still get the P0446 code when I drive about 100 miles......(gmc yukon evaporative emission (evap) Vent system Performance) Help!

Mike, you said you used a fused jumper wire from the 5 volt ref to the signal wire, what amp fuse did you use?????

If everything is correct and wiring is OK and the light still stays on,do you think that re-flashing the PCM to stock would eliminate light?

I have a 2010 Chevy HHR with code P0446 and the readings are always around -12 mmHg and 2.82v tank pressure. Is that a large leak somewhere?

Well done, what a professional video! When you jump the 5V ref to the signal wire, would it ever be wise to add in a resistor, maybe 5k ohms, in line with the fuse so that any current through that wire would be negligible?

Thanks for the information! I have code p0446 for pontiac grand am. Would it be advisable if I change the fuel tank pressure sensor right away since i dont have a good scanner to test it?

Hi nice videos on mine car there is a problem when you open the gas cap you hear whoosh is that normal ? Especaly when its hot checked the purge valve its opening also there is no check engine light

Well Done Video!!Question: Can I replace the Fuel Tank Pressure Sensor on a 2007 Avalanche without removing the Gas Tank as well?Or should I remove the Tank? Also, would it have been better to connect the wire before installing the new sensor ?

If the sensor is bad can it be driven without any detrimental effects on the vehicle? Will it affect the gas mileage or anything else? And going at highway speeds will it damage anything further? We have a 2005 Chevy Silverado.