How To: Replacing the Charcoal Canister

My CEL had been on for almost a year, and now I needed it off to pass the NYS annual vehicle inspection. My mechanic friend read the code. The dreaded P0446. The vehicle: 2003 Tacoma 2.7L automatic extended cab with 155K miles.



After searching on the code number, it became clear that the evaporative canister was the most likely suspect. It can be smoke or vacuum tested to further diagnose this as the source of the code.

I shopped for the part, and found one (new-genuine Toyota part) on eBay for about $100 less than the local Toyota dealer’s price. I did buy the assorted hose clamps from the local dealer though.



I’m not going to kid you, but removal and replacing the canister is no picnic. This is particularly true for a 2003 that lived most of its life in Maine. The canister is located above the gas tank, and is therefore exposed to the elements. They take their toll on steel parts, and mine was no exception. Should you so desire, you may remove the bed for easier access. I had neither the desire nor the means to do so. The canister is removable from underneath, even when it is in a deteriorated condition.

FOLLOW SAFE JACKING PROCEDURES ANYTIME YOU ARE WORKING UNDER A VEHICLE! CHOCK THE WHEELS AND USE JACK STANDS OR SOLID BLOCKING. NEVER RELY ON THE JACK ALONE. THIS GOES EQUALLY FOR A TWO-MINUTE OR TWO DAY JOB. YOUR LIFE IS WORTH THE FEW MINUTES IT WILL TAKE YOU TO WORK SAFE.

I did not need to jack up the rear end due to a small lift from my Wheeler’s 5 leaf springs. Chock the wheels and remove the spare tire. Once the tire is removed, do yourself a favor and wrap a couple of rags around the spare tire brackets. Your head will thank you for that every time you bang into one of them trying to get a better look.

Take pictures before you start. This way you will be able to see where the hoses connect when you have the new canister installed. I found that the shape of the hoses made it pretty easy to reconnect everything, but a reference picture or two will help insure everything goes back on the right way.



The front mounting bolt is accessible from the driver’s side rear wheel well. The bolt is on the frame forward of the axle. Yes I know my fender flare is missing. It’s OK; it’s back on now.



Working from the rear of the vehicle, disconnect the hoses on the right side of the canister. You need to remove the valves in order to have easier access to the mounting bolts. Mine were rusted beyond the point at which they could have been removed, so I cut the mounting bracket with a hacksaw blade. The new canister includes the mounting brackets.



As you can see, the mounting bolts for this bracket are in tough shape. They were eroded down to a size and shape that no wrench could grab. So out came a cold chisel, with which I hammered the head of the bolt a little off center to the right side and slowly broke both bolts free. As you can see, they were both soaked in PB Blaster for a day or so. Once they were loose, I was able to latch on with a wrench and spin them out. The chisel will severely tear up the head of the bolt, so it may take some trial and error to find a wrench that will work. It took and hour to break them loose, and only a few minutes to spin them out. You do not want to break the bolts off, so take your time. They will move. You may be able to use a Dremel tool to grind a flatter surface for your wrench on the head of the bolt after you have it loose. I do not recommend using a torch to heat the bolts as you are only an inch or two from the gas tank.



Remove the mounting bracket from the new canister and fit the canister into position. There is enough wiggle room to bolt the mounting bracket to the frame, and then to attach the canister to the bracket. Put the front bolt in from the wheel well before you tighten everything. I used three stainless steel bolts to install the new canister brackets to the frame.

Reconnect the hoses and electrical connections. The bracket on the wheel well side has a spot to hold some abs brake wiring in place.

A few pictures of the new canister after it has been installed and connected:





Here’s the old one. Quite rusty and malfunctioning.



After reassembly, I had an additional code come up for the downstream O2 sensor, so that was also replaced. The codes were cleared, and I drove about 75 miles. No CEL, and the truck passed inspection the next day.

Two months later I noticed an unexpected benefit. My fuel economy has increased by about 60 miles per tankful. I am now averaging over 20 mpg. That may be mainly from the O2 sensor, but I’ll attribute it to the entire job. That makes me feel that this expensive part was worth the time and trouble to install. Another reminder; do not overfill your gas tank or you may flood the canister. If that happens, you will be redoing this job sooner than you had planned.

 

Is this the same for a 3.4 L engine? a local shop said the canister needs to be replaced but wanted 500$ to do it. I found the canister online for 180$ so i was going to try and do it myself.

 

Canisters hardly ever go on these. Get your fuel tank smoke checked if its not too late. If you don't keep over-filling your gas tank, you should be ok as far as the canister is concerned. At that mileage your fuel tank may have pinholes at top near straps. This cause a NO VAV POSSIBLE scenario which triggers that code. Camrys and Corrolas get the bad canister due to the fact that they are plumbed low. When fueling , once it stops do not keep sqeezing or rounding up... just stop.

 

you can unbolt the bed6x 17mm from underneath, unplug the rear lights and either remove it or safetly prop it up on the drivers side(remove the 3 drivers side bolts and loosen the passenger side ) with 2x4 boards and easily remove the canister

 

I agree, canisters probably hardly ever fail on Tacomas. I don't think mine was bad. But the VSVs do go bad. Toyota does not make the canister VSV available for sale, just the whole unit. I have since had to change another evap VSV. That said, I thought I found the canister VSV on-line somewhere (don't remember where), but I had already finished this install by then.

It also would not be a bad idea to raise, or remove, the bed. It's not that hard to do if you have some help, and if the bolts are not rusted solid. Check out some of the threads on bed removal.

DON'T OVERFILL YOUR GAS TANK! That's probably the main reason for problems with the canister. Two years later and I have no codes-no problems with the evap system (excepting the other bad VSV for evap under the hood last fall).

 

The FSM instructions look to be the same for the 3.4, however I did not check every detail.

If I were doing this again for someone, I'd want $500 too. Doing it for yourself however is a different story. We will put up with a lot to save some money.

 

Ive always made sure to stop filling as soon as the pump clicks maybe one or two times i over filled could have caused the issue. As far as i know my local shop did the smoke test and found the canister to be the problem, Before i replace i may inspect the old one for cracks or leaks and go from there.

 

Just finished this job today. Took about 3-4 hours and 3 beers. This would probably take an hour or two but there are always some bastard bolts that are stripped or stuck that make it difficult. Anyway, thanks for the write up! You saved me hundereds of dollars with this "how to" i appreciate it. Ill check back after emissions to see if i pass

 

no. the cannister for the 3.4 is in the engine bay. i changed mine about 6 months ago at about 206k miles. took maybe 5 minutes with all simple tools. my cannister came with a new vsv and purge solenoid so i only unpluged the vacuum lines, 2 electrical connectors, 3 bolts holding the whole thing down and reversed it all quite quickly.

 

also. the cannister was clogged to shit. and working at carquest, i ordered the new one in to test out and it wasn't clogged at all. thats how I knew it needed to be changed. MPG increased slightly

 

I'm glad that it helped. Since you are in the NE, this was probably a PITA to do. When I look look at my frame, I dream of the desert SW. Good luck with the emissions test.

 

Does that depend on the model year? I'm looking at the FSM for 2003s and it shows the 5VZ canister above the fuel tank-same as the 3RZ.

 

huh. it is i guess. according to this website, the cannisters are all missing from the area above the front driver tire wheel well. but then again. mine's a california model. maybe that affects it as well.

 

Later year first gens the evap was moved above fuel tank. 2003 and 4 for sure. I believe 2001 and 2. But not completely sure on those 2 years.

 

Tha

Thanks! @mechanicjon I haven't had any problems with mine. But I have noticed when filling up if I take the gas cap off right away and try to fill up, it reacts the way everyone is describing in this thread. So I take my gas cap off, then go pay and then fill up and I have no problems whatsoever. I think leaving the gas cap off for a few minutes let's all the vapors escape and makes for an easier fill up. At least it works for me. But it could also be the placebo effect. Lol! And I have 257,000 miles on the truck.

 

01 was the last year for canister under hood. 02 and up were moved to above the tank.

 

GHS57 did a good job of showing me how to replace the canister on my 2003. The one suggestion that will help make the job easier is to use a Dremel to cut off the existing bracket. Once I got access to the bolts they were easy to remove with a socket. If your bolts are badly rusted you might find using a stripped head removal socket much easier than a chisel. The connection used for the large hose is removed by compressing and buckling the ring on the canister side and pulling the hose straight off.

 

mine's a california model. maybe that affects it as well.

Yeah, California ones probably have three or four canisters spread around the system

-Mike

 

Nice write up! I just changed all the hoses on mine while I had the bed off.

 

This thread helped tremendously. I was dreading the job, but it only took me 4 hours to complete.

Bought:
OEM vapor canister (#7774004010) - $243.17
*3 x new mounting bolts (#9008011180) - $0.92 each
*Fender Flare Clip Kit - Amazon $9.99
****Cheat sheet parts. You might destroy the mounting bolts so pick up a spare set. Also, buy a fender flare clip kit for when you remove the rear driver flare and destroy. every. single. clip.

Biggest tip is to separate the canister into smaller components for easier manueverability while reinstalling.

To separate the vapor canister from the bracket remove:

Red - canister bracket. 2 x 10mm bolts (dots correspond to location of bolts)
Blue - disconnect the two small hoses from the solenoid
Purple - remove

I installed the bracket first, then the canister, and last reconnected the hoses.