The tC is getting older so this should be more comment, I've gone through 2 gas caps in the past 3 years.

 

had these codes myself and replaced the gas cap... i didnt reset the ECU and the light came off by itself after the 2-3 day of having the new gas cap installed...



i guess gas caps on the tC's are pretty faulty...

 

Late to the party, but..
What are you guys buying for gas caps? OEM or AM?
Thanks

 

i bought my cap from ebay for like fifteen bucks i think. it was toyota oem.

 

thnx

 

Yes, only buy OEM Toyota gas caps, I just bought one last week cause I threw the evap code again, I'm going through one every 2 years..yikes....imagine how long the none Toyota brand ones last.....

 

Just curious...WHY haven't you guys form descendant designed a far superior gas cap yet, with the cool descendant logo? Hummm I would definitely pay for that.

 

i've had this tC for almost 6 years now without any gas cap problems. i don't know what crazy stuff you people do to your cars that cause the problems that would require a gas cap replacement.

 

You know, take them out to dinner maybe get them a little drunk and take advantage of them when they are out. You know just general wear and tear.
I can click the gas cap as much as I want, but when I go to release it it just slides out, the mechanism that keeps it sealed is not quite working anymore to make a seal.

 

i click the sh-crap out of mine every time i fill up.. and with over 104K miles on this sucker.. i've filled up plenty of times.

yes the cap seems to come off easily whenever i loosen it, but perhaps there's other factors that are playing in prevention of a good seal for other people... just wouldn't really know what it can really be.

 

I have no clue? I have treated my car like it is gold, careful to even not drop gas on the paint, but for some reason they fail? I have heard of people just getting it replaced and boom codes gone. I have the scanguageII so engine light go by by. I'll replace the gas cap when I get some money and time.

 

I just recently changed my gas cap to fix the problem and its only been 5 months. the light engine light is on again and it says the problem is p0456 evap system small leak. That is too short to have a new gas cap replaced again! Are you sure theres no other problem?

 

https://www.scionlife.com/forums/sho...0&postcount=39

 

my CEL came on... i think they mentioned something about the purge system or purge valve... not really sure whats going on. how much it would be.

 

I don't frequent these forums anymore, but I thought I'd chime in. My CEL is throwing the P0456 code. I tightened the gas cap and reset it with my tool, but days later it came back on. My gas cap comes off really easily so I guess I'll buy a new one and see if that fixes it.

 

did that fixed it?

 

I'm having the same proble
With my gas cap. Ill click it a bunch of time and once I let go of the cap it just seems to pop out of place as if I never tightened it. My girlfriend has a tc as well and my gas cap works on her car... ? I'm so confused by this and even my neighbor who is a mechanic has no idea as to what the problem might be.. Any suggestions?

 

3 days ago I went to smog my tC. It passed with flying colors. About 30 miles later my CEL came on. I went to a friends shop and had the him look up the code/codes. The only code that came up was P0456 "EVAP" small leak.

So i'm heading out to Toyota/Scion to buy a OEM gas cap. I do not know why these caps are going bad I have 65,000 miles on my 2006.

I will reply back in a few weeks once the CEL code P0456 is off.

 

CEL (Check Engine Light) code P0456

What does that mean?

The Powertrain Control Module (PCM) at different times performs various tests on the EVAP system. OBD II Enhanced EVAP systems are in place to keep fuel tank vapors from venting into the atmosphere, and instead purges them into the engine to be burned. Regular pressure tests are conducted by the PCM to monitor the sealed system for leaks. The PCM monitors the EVAP system pressure by watching the fuel tank pressure (FTP) sensor. When the sensor indicates a small leak in the EVAP system, this code is set.

Potential Symptoms

There will likely be no noticeable symptoms other than the Malfunction Indicator Lamp (MIL). This is because the EVAP system is a closed system and only controls fuel tank vapors, not engine management.

Causes

Usually this P0456 code is caused by an incorrect or faulty gas cap. Filling the fuel tank with the engine running could conceivable cause this code as well or if the cap wasn't properly tightened. Any of the following could also be the cause:

A small leak in any of the EVAP hoses or fuel tank hoses
A small leak in the purge valve or vent valve
The EVAP Canister may be leaking
Possible Solutions

First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

 

^thanks