Hello All,

I recently inherited my fathers 2004 xj8 after his passing. I helped him find this car about 10 years ago and found the “right” one after months of searching. He cherished his car and I helped along the way with small issues along the way. I’ve now had his car for 8 months and had to replace the hard brake lines that rusted through and nearly caused me to get T-boned when I hit the brakes going through a intersection and the pedal went to the floor! Luckily it was late at night with no incoming traffic and I avoided a possible very precarious incident.

After taking it to a local repair shop for all new hard lines to be replaced on the underside, a week later after my first outing the check engine light came on. I stopped by my local Advanced Auto for a scan and came up with codes P0456, P0442, P1111. I checked the gas cap and it appeared to be fine but I was wondering if this is a fairly common issue and if there are specifics I can look for. I feel like I was raked over the coals for the brake repair which they didn’t reinstall the belly pan correctly and left it hanging. I live in a small beach town (ocean city, md) with not a lot of options for repairs for Jags, at least none that I could find.

I also noticed, now I can’t remember to be honest if this was before the whole brake issue and crew check engine light, that under steady throttle input maintaining consistent speed the RPMs hunt up and down a couple hundred RPMs. I was wondering if the codes I listed could cause that issue or should I be looking for another issue somewhere else. Thanks again for any help or advise!

Joe

 

The dtc's indicate a leak in the fuel vapor recovery (EHAP) system. The fuel vapors from the tank are fed to the combustion system in a controlled manner, so there is a connection to the intake system. If there is a leak in the intake system, false air is drawn and this can lead to the unruly running behavior at constant speed.

It is a little difficult to give advice in your situation. A specialist workshop would pressurize the recirculation system with a fog machine to find the leak. The valves and lines run from the tank on the underbody through the front wheel well into the engine compartment and the throttle body. Finding leaks through visible inspection alone can be difficult, if you are lucky just a line has gone off from its connector.

Most of the time it's not a big deal, but it can be difficult to find.

Fritz

 

Hi Joe,

Two quick thoughts....

1/ When you mention that you have checked the fuel cap, when you fill up and refit it, do you just do it up finger tight or do you make the cap "ratchet"?
It is recommended to make it click 3 times to ensure a suitable seal is made. Caps can fail and it might be the cheapest part to initially replace.

2/ Any history of the fuel tank being accessed to inspect or replace the fuel pump or fuel gauge sender unit?
Sometimes those big O rings don't seat properly on the first attempt and you can get a small air leak that can cause EVAP issues.