A neighbor here has a really, really nice ’04 DII with only 76,000 miles. The truck has had a persistent P0455 fault over the couple years or so.

It’s interesting that the P0455 fault is not even mentioned in the RAVE and it’s also interesting that there’s very little on this or other DII forums about P0455, but it’s easy to find that it indicates a large EVAP system leak.

The RAVE lists these possible reasons for an EVAP system leak.

• Fuel filler not tightened or cap missing.
• Sensor or actuator open circuit.
• Short circuit to vehicle supply or ground.
• Either purge or CVS valve stuck open.
• Either purge or CVS valve stuck shut or blocked pipe.
• Piping broken or not connected.
• Loose or leaking connection.

He has replaced the gas cap more times than he should have, so that’s likely not the problem.

What little I have found suggests that a smoke test of the EVAP system would be the next best diagnostic step. (Could they have put the service port in a less convenient location?)

But we don’t have a smoke machine. I’ve used the cigar smoke test method (successfully) to find an intake vac leak on a different friend’s truck years ago, but in that instance all the possible leak locations were in the engine compartment and the port on the intake that is used on SAI trucks made doing the smoke test relatively easy and convenient.

That’s not the case for the EVAP system, so that brings me to the purge valve.

There is a lot on this and other forums about replacing the purge valve. It is listed as a possible reason for an EVAP system leak. It would be easy to try replacing it, but I don’t like just throwing parts at a problem.

The RAVE does list a P0440 code – Purge valve not sealing. It seems to me that if the purge valve was the problem the P0440 would be triggered in addition to the P0445. Does that make sense?

If y’all confirm it’s unlikely the purge valve is the problem I’ll go ahead and recommend a smoke test. Please let me know. Other ideas are welcomed. Thanks.

 

Not familiar with that evap system, but here's an approach I would take. Check out the sensor, probably a pressure switch, maybe a vacuum switch. Use low pressure compressed air to see if the system holds pressure, or search for the leak.

My truck gives a whoosh sound when I open the gas cap to refuel. That was only after replacing the vent tube between the tank and the filler assembly, the old plastic tube was all cracked up. It was fairly easy to see from the ground without jacking it up.

 

https://landroverforums.com/forum/di...41/#post736325

 

Thank you. Well that's embarrassing! I had forgotten all about my own post on the same topic, about the same neighbor's truck a while back! So it looks like it's on to the smoke test. Thanks again.

 

Tell him he can reach out to me, I have a smoke tester with an inflatable part that sits inside the air intake and lets the smoke in and keeps a very nice seal.