I've been battling a P0455 code for months, the jag has been in and out of multiple different Indy jag shops (local dealers don't service anything more then 10 yrs of age)! Every single piece in the Evap system has been replaced, hoses,canisters the CCV and purge valve, crossover tube all related tubing,fuel pump & tank fuel cap and so on. Every shop it goes to it comes back exactly the same way it when in! (Yes they are replacing things & not jipping me) in an attempt to find the cause. Yes they do diagnostics and can't figure out the cause including smoke test & a pressure test My newest issue is my 2nd new purge valve begins making a trumpet/mooing sound at stops & at average city speeds it's become annoying an embarrassment and a money waster. If any one has any advice or idea of what the heck on earth I am dealing with here, I'm ready to crush this car! Or call a priest.

 

I've read of this noise from a year or two back...with almost the identical description...so perhaps some Search use will prevail? Thing is, I don't recall the thread...hopefully someone will come back with an answer if you don't find it.

 

Well your not alone I'm on a chase to get mine running again, and nearly buried it next to the whipper snipper
Maybe you car is calling for mummy LOL.
sorry for that
anyway what is a P0455 code
and what happens if you erase/reset the code
just a thought

 

A 455 is an EVAP leak...the first, cheapest and quickest recommendation is a filler cap replacement. Then it goes from there all the way to the charcoal canisters. The most common replacement is the balance tube going between the canisters which I have to replace.

Here's a list of areas of possibility it could lead to (as OP Sean states) in Post #2... https://www.jaguarforums.com/forum/x...4/#post1517552

You can clear the code and it may come right back (that being its a bad part/leak) or it may be like mine...It may send a code in a month or a year, ...thus a small intermittent leak.

 

I've tried clearing/resetting the code it will clear and stay clear while a reader is connected to the obd, once it's removed the Check engine light comes back instantaneously

 

Hi Sean,

P0455 can be caused by a leak, but it can also be caused by an electrical issue. Here are the definition and possible causes from the Diagnostic Trouble Codes Summaries manual:




If you've ruled out all mechanical leak possibilities, the next avenue of inspection is the electrical circuits. I am attaching the Electrical Guide and the DTC Summaries, which should help a good Jaguar shop track down the underlying issue.

Cheers,

Don

 

I appreciate this greatly, I've screenshotted these for future reference! Late this week I seem to have found the issue, I decided to pull the purge valve out of the jag and bench test using a 9V battery some wires and my trusty Kirby vacuum that I ran a small tube from the vacuum side of the purge valve and taped it to the kirby's hose. Of course the purge valve made the loud trumpet sound, I also took the advice of a neighbor who owned an xj8 years ago to blow compressed air into all the tubing that connects directly to the purge valve. This morning (4/20/19) started the car noticed the CEL was on after letting her warm up I got in and shocker the cel was off the purge valve still makes the noise but I've order a new one and some dynamat insulation just in case!