2003 Toyota engine warning light

[Dom]

Our 2003 Toyota Avalon was left to us when my wife's mother passed, some years back. . It now has 117,000 miles on it & the engine warning light has recently come on. Our local mechanic said it was an evap problem. He had us replace the gas cap first. With his electronic analyzer , checked a couple more items. His final conclusion is that the charcoal canister back by the fuel tank needs replacement. Have to remove the muffler , & then fairly easy access. $221 for a new OEM canister plus the shipping. I guess about ( for me ) , 3 to 4 hr job. I have been told it in no way affects the performance of the engine. Gas mileage or performance. Do any of you mechanic guru's concur? Appreciate you informed advice. About 5000 miles a year is all we drive.

[Nobade]

There is the gas cap, tank vent valve, purge valve, charcoal canister, and assorted plumbing. That is really all there is to that system. First thing is, what exactly is the code it is giving you? The canister is the last thing I would replace, they very seldom go bad. They do, however, get liquid fuel in them from topping up the tank or fueling while the engine is running. The vent and purge valves can be bench tested to see if they are working. The lines can be smoke tested to find any leaks. But knowing the actual code is going to be the first thing.

[steve urquell]

The code is typically P0455 evap emissions leak. I had it on my wife's 2014 Hyundai. Dealer could not fix it and I gave up taking it to the dealer and bought a code reader and cleared it all the time.

My suggestion is to buy a cheap code reader and clear it. You may be able to find and fix the problem or you may throw hundreds of dollars at it with no resolution.

[Finster101]

If your mechanic told you to replace the cap first, he is just guessing. If the system has a leak and not holding vacuum then it should be sealed with a scan tool and smoke tested to find the leak. A decent tech with a good scan tool should be able to find the problem and not throw parts at it. Turned wrenches for almost 50 years before I retired.

[elmacgyver0]

the code is typically p0455 evap emissions leak. I had it on my wife's 2014 hyundai. Dealer could not fix it and i gave up taking it to the dealer and bought a code reader and cleared it all the time.

My suggestion is to buy a cheap code reader and clear it. You may be able to find and fix the problem or you may throw hundreds of dollars at it with no resolution.

"this"

[FLINTNFIRE]

Best suggestion on a toyota check engine light was put a piece of tape over it .

Gas caps cause it sensors cause it and does it really make a difference in the way it runs , I quit fighting mine years ago and let it glow .

[beemer]

The check engine on out 2006 van light kept coming on, could clear it but waste of time. When we had it checked and it was the catalytic converter, three different places said the same. The engine was getting sluggish and using more gas and smelled like rotten eggs. We had it replaced at around $1000 for OEM. The engine runs much better now, don't assume it is nothing.The van has around 230,000. We took it to our muffler shop guy, said most lasted 175-200,000. Our new one should finish out the van.

Our 1998 Camery has had the check engine light on since we bought it 23 years ago. Reader says low egr if I remember. We have had it fixed three times and it last about long enough to get out of sight of the shop. It doesn't seem to be any problem, has been the most reliable car we have ever owned. In the county we live in it is not a problem to get inspected but the next county over you can't.

[Martin Luber]

In my case, it was mice or chipmunks that chewed the connection wires on top of the gas tank. Dealer had changed gas cap, code reappeared in 2 weeks, then the canister for $1k, code in 2 weeks. Angry customer routine the third time. Trouble was they had to drop the tank to service it

[Recycled bullet]

What is the code? When you clear it how long does it take to reset the code?


A visual inspection with a bright flashlight will go a long way- inspect for cracked and damaged vacuum hoses, really common on Toyota V6, remove the plastic cover over the engine and just look around for broken tubing.

As has already been said bench testing the solenoids and cannister vent and vacuum switching valves is easy to do.

Is the O-ring split around the perimeter of the gas cap? If it's not your mechanic may be applying the parts cannon.

Many times on Avalon and Tacoma I have put the pressurized evap smoke and then spray everything with soapy water and look for where the bubbles happen more than once I have seen laminated fuel tanks fail cause a tricky and difficult to locate small leak.

[Dom]

OK. Now if I knew what a tank vent valve & purge valve is & where they are , & also how to smoke test. Are these valves under the hood. or back with the gas tank?

[Recycled bullet]

The purge valve is usually mounted near the intake and it is normally closed, it will be commanded open under certain conditions to allow intake manifold vacuum to draw negative pressure of the evaporative system / fuel system.

The vent valves / canister vent valve/ vacuum switching valves, there may be one under the hood, then the rest of them will be near the fuel tank and charcoal canister box, the purpose is to normally be open until it is commanded shut by the engine computer.

To perform self-diagnostic the engine computer will open the purge valve during engine running to draw a negative pressure while the purge valve is open, it will then close the vent valve. Thwre usually will be a pressure sensor AKA fuel tank pressure sensor. Then it will close the purge valve, sealing the fuel evaporative system. The amount of time that it takes for the pressure to neutralize to atmospheric is called vacuum decay and it will be usually a period of several minutes. Depending on the rate of loss of negative pressure will meet the criteria/ conditions that must be met in order to set a DTC or code.

[JonB_in_Glencoe]

I have a 2005 toyota Matrix (1.8 ltr). 7 years ago, I bought it with 220Kmi on it. The Chk Eng light was on then. Evap code. I swapped the gas cap. Chk eng light stayed off for 1000 miles. When it came on again, I cleaned the gas cap and removed the rust on filler neck where the cap would seal. That lasted another 1000 miles. That has repeated for a few years, then I gave up, as the cleanup quit working. I just started to ignore the light, I check codes when I change oil, incase some other code has fired. One time I had a different code fire and it needed new spark plugs. The plugs I removed looked OK, except the gap was near .100" (they should be around .044"). It's got 275Kmi on it now...evap code always on. I think the computer can sense a leak in old rubber seals on filler tube neck or tubes to canister or whatever. Doesn't effect my car.

[czgunner]

Its almost never the gas cap. I'm a Toyota trained tech and did driveability diag when I was wrenching. The evap canisters on those fail pretty often. Also check for a possible TSB for an updated fuel neck to keep water out of the canister. You need to find a better "mechanic" who knows how to diagnose instead of guessing and throwing parts at problems.

Sent from my Pixel 3 using Tapatalk

[Dom]

Wow, wow, wow!!!!!

[ebb]

Me "Can you put a new fuel pump on my truck?" My mechanic Ruben " Not till I hook up my lap top and find out if it needs a fuel pump." One day later me "Was it the fuel pump?' Ruben "no it was a crank shaft position indicator." After research fuel pump and labor $500 plus, Crankshaft position indicator and labor $110. Ruben "You know how depressed I get when I replace parts that don't need replacing."

[.429&H110]

I know you are not in Alaska but
My 2001 tacoma would light that light every time I left it out in the cold overnight.
The block heaters pulled 10 amps, maybe shoulda heated the canister too.
The canister would freeze solid light the light...
A sourdough told me to get a cheap code reader
reset the thing after a night in a warm garage.
He said that is all the dealer does.
Sometimes a whack with a rubber hammer helped to loosen the charcoal.
So every once in a while I reset the code.
Another routine code was the battery would freeze, the oxygen sensor would see low voltage.
Light the light.
I had to agree, yup less than 8 volts.
Change the sensor or the battery?
Code reader paid for itself for sure.
I miss that truck.

[45DUDE]

More than likely it's the purge valve solenoid- $25-. My Maxima needed one 10 years ago so I bought one and never put it on. Light still on. I bought an OBD $50 scanner for my three computer control vehicles and scan when the light comes on. o2 sensors -egr control solenoids and purge valves are common in my area. I know one shop that replaces the gas cap on everything with a check engine light and turns the light out. The light may stay out a few days and they put more parts on.

[Thin Man]

Trouble lights by themselves are a threat to your sanity. My '96 Dodge Dakota has 2 lights that would not go off. They are the ABS (anti-lock brake system) light and the Brake light. Being that I don't want to lose brake function on any vehicle I am driving, I started calling repair stations. The first claimed these lights, when both are "on", signal pending brake failure, with an estimated cost of $1,800 to repair the problem. The next call was an eye opener. The repair coordinator claimed all I needed to do was fill up the master cylinder with brake fluid, should make the issue go away. That was where I started as I had a can of brake fluid on the shelf. I parked the truck on a very level part of my driveway and removed the top cap from the cylinder. It was divided into 2 separate chambers. Both of these were about 70% loaded with fluid. Filled the front half so it would take no more fluid, then the rear half to the top, then replaced the top cover. Fired up the engine, and guess what. Both warning lights were off. All this happened about 4 months ago and both lights are still off. Isn't it satisfying to correct a challenge like this with simple maintenance.

[Finster101]

Trouble lights by themselves are a threat to your sanity. My '96 Dodge Dakota has 2 lights that would not go off. They are the ABS (anti-lock brake system) light and the Brake light. Being that I don't want to lose brake function on any vehicle I am driving, I started calling repair stations. The first claimed these lights, when both are "on", signal pending brake failure, with an estimated cost of $1,800 to repair the problem. The next call was an eye opener. The repair coordinator claimed all I needed to do was fill up the master cylinder with brake fluid, should make the issue go away. That was where I started as I had a can of brake fluid on the shelf. I parked the truck on a very level part of my driveway and removed the top cap from the cylinder. It was divided into 2 separate chambers. Both of these were about 70% loaded with fluid. Filled the front half so it would take no more fluid, then the rear half to the top, then replaced the top cover. Fired up the engine, and guess what. Both warning lights were off. All this happened about 4 months ago and both lights are still off. Isn't it satisfying to correct a challenge like this with simple maintenance.



Your next question is where the fluid went.

[steve urquell]

Your next question is where the fluid went.

Takes up the space in the calipers as the pads wear. With wear the caliper pistons are farther out and the fluid goes into that space. When you change the pads it gets pushed back into the master cylinder.

[Finster101]

Takes up the space in the calipers as the pads wear. With wear the caliper pistons are farther out and the fluid goes into that space. When you change the pads it gets pushed back into the master cylinder.

Yeah I know all that, but if it is low enough to turn the light on those pads have to be getting pretty worn. I have done a lot of brake jobs in my career.