Question for you and a little back story....

I had the P0456 code a while back. Basically did nothing about it because it was running fine. Then one day it wasn't running fine. Had to replace the valve cover gaskets because the inner gaskets leaked oil into the plug wells. At that time I also replaced the upper intake gaskets.

When I put it all back together it ran great and bonus.....the P0456 code was gone. I have driven it for about 2 months with it running great and then yesterday out of nowhere the P0456 appears again and when having the heat on there is somewhat of a faint exhaust smell in the car. It isn't a fresh gas smell. Just a faint exhaust smell. This same smell existed too when I had this error code a while back.

I have checked the typical things that I have read on here such as a cracked canister and such by mine appears to be in good shape. On a side note....I have also had to replace the bank 1 O2 sensor twice in the last 3 moths......

I have also replaced the o-rings in the back of the intake manifold.

Car is running great! Just have to find this evap leak....

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2003 S-Type (addded by GGG)

 

Well we're assuming you have a jaguar, but that covers alot of years and models.

 

Welcome to the forum ronzues,

I've had to go to your forum registration to find out Model and Year details and add them to your post. I've also moved your question from General Tech Help to S-Type forum. This is the place to post technical questions about your model.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Okay! Will do. Thank you!

 

Why did the O2 sensor have to be changed twice?

Did you use the proper kind?

 

I'm not really sure why. I had a code for it awhile back (before I ever got the P0456 code) so I replaced it and the code for bank1 sensor 1 went away. Then a bit later the P0456 code showed up. After having the valve cover gasket leaking problem and replacing the gaskets and putting it all back together I again had the bank 1 sensor 1 code so I replaced that sensor again. After that all codes cleared on their own and I have been code free for 2 months or more until a couple of days ago when the P0456 showed up again.

I assumed that maybe the first O2 sensor that I bought was just too cheap as I got it off the internet for about $34.99 so the second time around I bought one from Auto Zone for about 3 times that amount. Who knows...

 

That's very odd - and I think unique.

P0456 can be tough to find due to the small size. I think techs use SDD/IDS to help but have never had to fight a P0456 myself.

 

Small evap leak is almost impossible to find. Ie i can put a hole in a hose and smoke test it knowing where i put the hole in the hose and cant see smoke. Sooooo we tell customers that this code is a go after the known areas as in purge valve, cannister close valve. Fuel tank seals and then last resort drop the tank and epoxy the not servicable valve in the center top that sometimes crack.

 

MyPo456 was the purge valve that Brutal mentions.

 

 

I've had that code twice and both times found the gas cap gasket had a hairline crack. Easy fix - might check that.

 

I will check that right now but would that cause me to have a faint exhaust smell in the cabin?

 

Also if the purge valve were bad it would be stuck open right? Meaning that I would be able to remove it and blow and suck through it and feel it at the other port?

 

That does not sound likely for such a small leak.

 

Yeah I guess you have a point there....

 

no the seal and seat can leak. same as gas cap seal. and a note on gas caps, DO NOT GET ANYTHING OTHER THAN OEM. Aftermarket suck and we have to replace new aftermarket caps all the time. Also smear the seal on the gas cap with Vaseline to lube if you think it might be a issue

 

Does the fact that I have a faint exhaust smell in the cabin when the heat is on give any indication of where I should start looking or better yet what I can rule out?

For instance, if it were the gas cap or the charcoal canister would I smell it when the heat is on or would that indicate that the problem is likely under the hood, purge valve?
It is a faint exhaust smell, not a gas smell.

 

Exhaust has nothing to do with the evap system.

 

Well I know but "faint exhaust smell" is the best way that I know how to describe it. It is definitely not straight gas fumes and I have only smelled it since the p0456 code showed up. Had the same smell the last time that this code appeared.

 

Realistically you need to do work on the actual car.