[CWilder]

Well, I decided to try a new intake that I got for cheap... its pretty nice. I moved the VSV at the airbox and replaced the two vacuum hoses at the VCV. I think airflow is much better. I found I had a crack/leak in the old airbox. Could that have caused a problem here?

 

[CWilder]

300 miles later, P0442 has returned.

 

[ill_mannered]

Unfortunate. There must be a leak somewhere in the system that hasn’t been tracked down yet.

 

[CWilder]

Ok, I capped the vent at the canister and smoked the system again. Could not see any leaks. It was able to build pressure. Applied power to all three VSV and they all "clicked". I am trying to think of the remaining possibilities.... Tank leak, filler neck, new gas cap bad, VSV stuck open, vapor pressure sensor bad. How should I verify the VSV or sensor is bad?

Can I delete that little EVAP black box in the lower photo?

Also, P0440 and P0442 have BOTH returned.....

 

[theraflu]

Do you have access to a scan tool or just a code reader?

 

[ill_mannered]

Is that little black box cracked? Fuel filler neck would be hard to see smoke coming out of it. It could have a bad coupling. Considering all the VSV clicked when you tried them, I wouldn’t think one is stuck open personally.

 

[01 SolarYellow]

When you checked the vsv's did you blow or suck to make sure they do not leak?

 

[ill_mannered]

In theory a bad FTP sensor could cause these codes. However you would sometimes get a P1453 with these other codes pointing you to a faulty FTP sensor. I hate EVAP codes in general. They can be easy or downright impossible to figure out at times.

 

[CWilder]

Do you have access to a scan tool or just a code reader?

Just a code reader.

 

[CWilder]

When you checked the vsv's did you blow or suck to make sure they do not leak?

I only checked to see if they clicked, was not sure how to setup a test to see if they leak across or are stuck in position. They all made a strong click sound, I just powered them with a 12V battery.

 

[CWilder]

In theory a bad FTP sensor could cause these codes. However you would sometimes get a P1453 with these other codes pointing you to a faulty FTP sensor. I hate EVAP codes in general. They can be easy or downright impossible to figure out at times.

These EVAP problems are extremely frustrating. I wish I could figure it out or disable the codes for these errors only. Don't really want to spend more money guessing on this issue.

 

[theraflu]

With no scanner this makes it harder to diagnose the vapor/fuel tank pressure sensor. Basically it should read vacuum with the purge valve on and vent closed. It should read no pressure with the gas cap off. The sensor is what passes the onboard monitors so a stuck signal is very possible. As far as the solenoids, a click doesn’t mean much.

 

[01 SolarYellow]

I only checked to see if they clicked, was not sure how to setup a test to see if they leak across or are stuck in position. They all made a strong click sound, I just powered them with a 12V battery.

Take the solenoid in your hand and blow through it. Then activate it. It should seal and pass air as you activate and deactivate.

 

[CWilder]

With no scanner this makes it harder to diagnose the vapor/fuel tank pressure sensor. Basically it should read vacuum with the purge valve on and vent closed. It should read no pressure with the gas cap off. The sensor is what passes the onboard monitors so a stuck signal is very possible. As far as the solenoids, a click doesn’t mean much.

The only thing I was testing was if they reacted to any voltage. They did, that's all I could do with that limited test

The codes come on independently of each other and usually at intervals of 250-350 miles

 

[CWilder]

I have all but given up on this 0440 an 0442. They are popping up every 150-300 miles now. So twice a week for me... I replaced almost every hose, a VSV, check valve on top of gas tank, gas cap....

 

[01 SolarYellow]

I have all but given up on this 0440 an 0442. They are popping up every 150-300 miles now. So twice a week for me... I replaced almost every hose, a VSV, check valve on top of gas tank, gas cap....

If you have a 2002 to 2005 ECU. You can send it to Quantum Auto or Xat racing and get it remapped. They can remove the rear O2 and the Evap codes permently. Along with some other tweaks.

https://quantum-auto.com/ols/products/ecu-re-map-service-ecu-re-map-srv

XAT ECU Re-Map for IS300, 3UZ and Newer LS430 SC430 GS430 2002+

Please note this remap service. You will need to send in YOUR ECU that we will modify for you. Please note we cannot offer this service for 2001 model year IS300sRemap service is available for any 3UZ ecu, as well as any GR and UR and some others SUCH AS THE IS300 2JZVVTI!!!!. Achieved are:Zero...

xatracing.com

 

[CWilder]

Well, still chasing 0440 and 0442 evap codes. Got a charcoal canister assembly from a parts car and installed it yesterday. Waiting to see if it helps.

 

[kbswagner]

Well, still chasing 0440 and 0442 evap codes. Got a charcoal canister assembly from a parts car and installed it yesterday. Waiting to see if it helps.

Did this solve your issue?

 

[01 SolarYellow]

Did this solve your issue?

There is no problem that will be the same from car to car. You must test and inspect. To find your issue.