Hello, my jag seems to run fine until I put it in park and let it idle. After idling a few minutes, the engine will shake a bit and the check engine light illuminates. There is a hissing close to the intake. I am going to change the o-rings in the crank case breather pipe fittings tomorrow. The hiss seems to change when I move the fittings around. Is this a common place for a leak? Is there any other probable causes of the hiss?

Codes: (The codes all seem to include an evaporative leak)
p0112
p0456
p0442
p1111

Thanks, Kelby

 

Also, when re-starting the engine after it is hot, the rpm's drop below normal and the engine almost stalls. After almost stalling, it idles normal.

 

It may be the valve itself has a crack.

Any hiss is very bad news as the unmetered air causes bad running.

You can try small amounts of a burnable gas like propane and watch fuel trims to see where a leak is or a smoke test.

 

@ JagV8- I used some carb cleaner around the intake, and could not find a leak, anywhere! I can hear a faint hiss. Do these cars normally make a faint suction/hiss noise? Also, I have read that the front 02 sensor may be my problem.
Codes- p0171,p0174,p0456,p1316

 

Should have no hiss and you have air leak codes. You need better diagnosis such as a smoke test

 

Have you cleared the codes and then see what comes back?

It's hard with multiple codes so make sure they are all repeatable.
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I had the codes cleared.
Here are the new codes:
p0171- system too lean bank 1
p0174- system too lean bank 2
p0442- evap leak
p0456- evap leak (very small)
p0171- system too lean bank 1
p0101- mass or volume air flow circuit range/performance problem
p0456- evap leak (very small)
p1111

 

I'd fix evap leaks first and see if the rest then do not occur.

 

The small leak can sometimes be a bad or not all the way latched gas cap.
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Sorry guys, I have been very busy. Going to school full time…...

Last week, I completely filled the fuel tank. When I Walked to the driver side (left side), I noticed about a gallon of gas had leaked onto the ground. I lifted the back seat and noticed the top of the gas tank on the driver side was wet. I bought a new gasket from jaguar (part number: XR857245). It is the green gasket. I installed the new gasket and it still leaks when fueling up. What to do now?

It has two codes: p0442 and p0456

 

You need to go back to the hissing sound under the hood for the two EVAP codes. The check valve on the left side is quite often the cause.

The leaking gas is a different issue.

 

I had the car smoke tested. The mechanic found a small vacuum leak and he repaired it. Sorry, that was an old issue.

I took the gas tank seal back off today (driver side seal), and I found the plastic piece that the clamp fits on has a hairline crack in it. I will order that piece and hope that fixes it.

The jag dealer said the codes "p0442" and p0456" can be associated with the gas leak.