Posting this to document a strange set of conditions for someone in the future with a similar problem.
2002 4Runner with about 250k miles on it.
The first condition that began this whole adventure was difficulty starting the engine when it was hot. The best example was a stop at the gas station. I'd shut the engine off, pump gas for a few minutes, and attempt to restart. The engine would start, and then immediately die. I would then need to crank the engine for 4-5 seconds before it would restart. No issues driving after that.
My first inkling was the fuel system. The fuel filter was due for a change, so I started there. No change to the problem.
I then went to the MAF sensor and throttle body, and decided to clean both of those just to rule them out. While doing that, I notice a hole on the underside of the vacuum line that goes to the air intake. "Ahh, here's the problem!" I thought, and replaced the vacuum line.
A few days after changing the vacuum line, I started to get P0440, P0441 and P0446 codes intermittently:
============1==============
P0441
Raw code: 0441
ECU: 10
Status: Pending
Evaporative emission (EVAP) system - incorrect flow detected
Evaporative Control Incorrect Flow Detected
============2==============
P0440
Raw code: 0440
ECU: 10
Status: Pending
Evaporative emission (EVAP) system - malfunction
Evaporative Control System Malfunction
============3==============
P0446
Raw code: 0446
ECU: 10
Status: Confirmed
Evaporative emission (EVAP) system, vent control - circuit malfunction
Evaporative Control Vent Control Malfunction
This usually happened on my morning commute after driving for about 3-4 minutes. Since I had changed the long vacuum line in the engine compartment, I decided to try the easy road and change the vacuum switching valve that was at the other end of the line. Despite it having a good deal of rust/corrosion on the mounting bracket, it was still functioning normal and wasn't the culprit.
After lots of searching, I decided to go after the VSV that was on top of the charcoal canister. Under the truck I went. While I'm not in the worst part of the rust belt, 22 years had rusted all 4 mounting bolts for the canister, and I ended up having to drill/tap 3 of the 4. Drilling an tapping was a total pain because of the frame member that is in the way for the forward bolts. The aft bolts were gentlemanly with the spare tire removed.
When I removed the canister, which is required to get to the VSV, I noticed that the canister itself sounded like an etch a sketch when you would move it side to side.
After some light troubleshooting, I decided to replace the entire canister. Based on the age of the truck, I decided to go with the aftermarket Dorman one, rather than the Toyota part. Photos of the old and new canisters are attached. The nice part is that the new canister included all new hoses and a new VSV, so hopefully I never have to touch that thing again for the life of the truck.
Because of the bolts, if you're going to drop that canister, I recommend you just replace it in the process. It was a pain and about 2-3 hours to complete. I'll be happy if I never have to touch that thing again!
Hopefully someone else finds this helpful!
2002 4Runner with about 250k miles on it.
The first condition that began this whole adventure was difficulty starting the engine when it was hot. The best example was a stop at the gas station. I'd shut the engine off, pump gas for a few minutes, and attempt to restart. The engine would start, and then immediately die. I would then need to crank the engine for 4-5 seconds before it would restart. No issues driving after that.
My first inkling was the fuel system. The fuel filter was due for a change, so I started there. No change to the problem.
I then went to the MAF sensor and throttle body, and decided to clean both of those just to rule them out. While doing that, I notice a hole on the underside of the vacuum line that goes to the air intake. "Ahh, here's the problem!" I thought, and replaced the vacuum line.
A few days after changing the vacuum line, I started to get P0440, P0441 and P0446 codes intermittently:
============1==============
P0441
Raw code: 0441
ECU: 10
Status: Pending
Evaporative emission (EVAP) system - incorrect flow detected
Evaporative Control Incorrect Flow Detected
============2==============
P0440
Raw code: 0440
ECU: 10
Status: Pending
Evaporative emission (EVAP) system - malfunction
Evaporative Control System Malfunction
============3==============
P0446
Raw code: 0446
ECU: 10
Status: Confirmed
Evaporative emission (EVAP) system, vent control - circuit malfunction
Evaporative Control Vent Control Malfunction
This usually happened on my morning commute after driving for about 3-4 minutes. Since I had changed the long vacuum line in the engine compartment, I decided to try the easy road and change the vacuum switching valve that was at the other end of the line. Despite it having a good deal of rust/corrosion on the mounting bracket, it was still functioning normal and wasn't the culprit.
After lots of searching, I decided to go after the VSV that was on top of the charcoal canister. Under the truck I went. While I'm not in the worst part of the rust belt, 22 years had rusted all 4 mounting bolts for the canister, and I ended up having to drill/tap 3 of the 4. Drilling an tapping was a total pain because of the frame member that is in the way for the forward bolts. The aft bolts were gentlemanly with the spare tire removed.
When I removed the canister, which is required to get to the VSV, I noticed that the canister itself sounded like an etch a sketch when you would move it side to side.
After some light troubleshooting, I decided to replace the entire canister. Based on the age of the truck, I decided to go with the aftermarket Dorman one, rather than the Toyota part. Photos of the old and new canisters are attached. The nice part is that the new canister included all new hoses and a new VSV, so hopefully I never have to touch that thing again for the life of the truck.
Because of the bolts, if you're going to drop that canister, I recommend you just replace it in the process. It was a pain and about 2-3 hours to complete. I'll be happy if I never have to touch that thing again!
Hopefully someone else finds this helpful!
