June1978

2002 ES300

Got CEL P0442 (small EVAP leak)

While the car was running, I took off the gas cap and put it back on. Also went under the hood and saw a small hose that was not connected properly to the air box. Came back to the car and saw VSC and Trac off lights blinking. I cleared the CEL and turned the car on and off. After about a minute the VSC and Trac off lights come back on and stay on.

I'm thinking vacuum leak but thinking I should replace gas cap first- ideas? Thanks

Arsenii

Hello,

Small leaks are usually not that easy to make out by looking at the hoses unfortunately.. I got a P0440 once, I knew it was a gas cap since I can distinctly smell the fuel coming out of it, so I got a new OEM gasket for the cap (P/N: 77316-16010), but it didn't fix the issue. Turned out that my ratchet in the cap is starting to go, so it wasn't tightening all the way, I need to push on it a little harder than usual to get it to bind properly, though the good news is that P0440 never came back ever since..

If you are going to replace the gas cap, only use OEM one, not all of them can be trusted, but if that won't help, it may be a good idea to get the system smoke-tested before you will go to swap any other parts. Before you commit to a smoke test though, you check all the hoses around the charcoal canister and under the hood for any signs of cracking or other wear, and also check that VSV valves operate as intended.

Hope this helps and best of luck!

June1978

Got this resolved. TRAC off and VSC light were on. Mechanic pulled a code (forgot number but starts with a C). He had to recalibrate a sensor.....he also ran a EVAP diagnostic and all is well.

I did replace the gas cap and fix the split hose going into the air box so he think the P0442 was from one of those components

Easy fix- I was in and out in 30 minutes. All is good - for now

June1978

If anyone cares- it was code C1336 and zero point calibration needed to be done. Repaired VSC and Trac light issue

take care