2012 Outback 2.5, approx: 75,000 miles. She was driving on the highway about 40 miles into a 65 mile trip. Check engine light and traction light came on, Cruise and Brake warning lamps started blinking. Apparently these lights normally come on all at the same time when the ECU sets a code of some sort. Seems excessive to me. 

 

Scanned it and got a P0456 - Evap System Very Small Leak. 

Checked the gas cap and it was on and tight. Removed it and checked the seal, and there was a fine silvery layer of what looked like lead all the way around the seal. In some spots it was fairly heavy.  Wiped it off with a rag and some light degreaser, also wiped around the filler neck where the seal makes contact. 

Reset the code and drove it about 30 miles while watching the monitors with my scanner and got the evap monitor to set about 5 minutes after I got on the highway. Rescan showed no new codes. Going to keep an eye on it and see if it pops up again. 

 

This seems to be a common occurance with these newer cars, and it looks like most people just replace the gas cap.

Wondering if simply cleaning the seal on the gas cap is something that could be done periodically to prevent this problem. 

?

 

not some residue from a sabotage attempt? what was the stuff you wiped off? just some zinc or 'plating' from the fill pipe or ?

Not really plating or residue.

Looked just like a thin layer of lead/graphite. It had the same metallic sheen like if you used a pencil to color on a piece of paper. Not greasy or clumpy or anything like that. Just some lead that probably rubbed off of the gas pump nozzle and got on the fill spout over the years, and it stuck to the seal and built up over a period of time.

 

I guess they probably use aluminum for gas nozzles now, since lead isn't kosher anymore.

Edited November 1, 20169 yr by Fairtax4me

yeah, I could see nozzle metal abrading and building up there, never really thought about it before.

 

considering all the vehicles those nozzles visit and hanging around outside all the time - they also could easily leave something behind that might compromise a seal i guess.

Edited November 1, 20169 yr by 1 Lucky Texan

Excessive - seriously, disabling everything for benign faults is odd, not a fan of that. 

 

 

Reset the code and drove it about 30 miles while watching the monitors with my scanner and got the evap monitor to set about 5 minutes after I got on the highway.

 

If the code came back - doesn't that mean the issue may, or probably is, still outstanding?

Code didn't come back. I was watching the emissions monitors to make sure the evap monitor set as "Ready", meaning the monitor ran through its diagnostic of the evap system and didn't find a fault.

 

Didn't have time to take it 65 miles and try to exactly replicate the drive she was on when the code set. She has to take it to the dealer this week anyway to have them perform a recall on it for something with the wiper motor/linkage. That's about a 60 mile drive round trip, and then she's making the same 65 mile trip again next week. Should find out pretty soon if it's going to come back.

oh i read monitor and thought CEL, my bad.