All:

Sorry for not finding a previous thread about OBDII code 0455 (Large EVAP leak)...I'd think it would be a relatively common issue, but the advanced search couldn't find any previous posts...

Anyway, I had my check engine light come on, and went out and invested in a very nice OBDII scanner. I tried it out this evening and got the 0455 code. I'm not 100% sure where the evap system might have a leak...but I did check JTIS and it seems like it's a pretty vague error.

Has anyone had any problems with this error code before? Any helpful hints or places to investigate? Am I still safe to drive the car? (Hope so, still gotta get to work!)

Thanks

Dave

 

I did a quick searcheroo for P0455 (you forgot the P) and found a very common problem. Either a vent tube, canister close valve (aka - purge valve). Here's a link to a thread where it was the latter, and fixed himself for $70. I had mine repaired at dealer for a few hundred, found to be the vent tube (rusting) and canister close valve.

 

Possibilities on P0455

Fuel cap off
Fuel cap seal defective
EVAP system leak (canister damage,
pipework damage)
EVAPP valve to ECM drive circuit open
circuit, short circuit, high resistance
EVAPP valve power supply circuit open
circuit
EVAPP valve to engine purge pipe
damaged / blocked / leaking
EVAPP valve operating vacuum hose leak
/ blockage
EVAPP valve failure

Fuel tank leak

 

That's my problem...in summary, the JTIS description of the code is (in summary) "Well, it could be a lot of things...and maybe even something else" !!!

I did get the "CHECK GAS CAP" message (which cleared) at the same time the check engine light went on. Maybe it could be as easy as that...or be a harbinger of other issues...

My plan is to schedule an appt with the dealership as I can't see anything wrong with the system. I'll drive the car normally and test the codes periodically to see if it clears on it's own. If not, I'll hopefully be an educated consumer when I go to the dealership and be able to help them narrow it down a bit and hopefully save a buck or two...

Dave

 

Thought mine was gas cap too, many do. New cap doesn't fix it.

I'm wagering on the purge valve. The vent tube above it corrodes and drops pieces into the valve...that's what jacks it up.

 

Check the connecting Hose between the evap cannisters inboard of the right rear wheel near the right front of the tank. I had same code and found that the hose had deterioated. 50 cents worth of 5/8 fuel resistent hose----Problem solved.

 

Not helpful, but not sure if Jag should be your only ride.