Hi all,

I am CONSTANTLY getting the SES light with error code P0456. I have taken the car in about 6 times for this issue and each time its either cleared and ignored or they replace a random grommet and tell me they've leak tested and everything is A-OK. Six turns of the key later, P0456. Its been this way since the day I bought this car (new in 3/05). Its driving me nuts. I can't pass inspection with this damn light, and if I clear the code, I can't pass inspection without drive cycles, which trigger the code.... Two trips ago into the dealer I asked them to replace the diagnostic pump and the charcoal canister after reading a thread on here. No, they replaced a grommet (after waiting a week for the part). They said they smoke tested the whole system at that time, and no leak.

This latest round, I just had it in on Friday of last week, there is no indication of any work done on the bill (just a message about how my pulley is triggering the knock sensor). I think its just been cleared and ignored again. WTF....does anyone have any experience with constant recurring P0456?

 

you can do 3 things... the first is threaten the lemon law if the dealer has had the vehicle 6 times for the same code...

The second is try another Mini dealer... besides the local Princeton dealer, Morristown Mini (which has been VERY good to me) is ~40mi from you as is another one in PA...

The 3rd thing you can try is start removing some of your Mods... the 19% pulley requires more fuel (esp. since your stuffing more air in via the CIA), so you might actually be going lean (do you have a wide-band 02 before the cat?)

Since you've had this issue from Day1, I'd go for one of the 1st 2 options as it seems unlikely the mods you've made caused the issue...

If you do bring it to Morristown, ask Rob or Mike (the service desk guys) to speak to Erwin, who is the lead tech and really knows stuff...
Mo'town Mini is not queasy about mods either... it seems a lot of the workers drive modded cars I had a nice long (30-45min) chat with Erwin about mods... what works, whats in the JCW package, what you can do for that cash (turbo-superchaging setup!) suspension, brakes, pulleys, exhaust, intakes... well you get the idea.

HTH, and Good Luck!

 

I've heard good things about Morristown, and I may try them. To date, I've been using a PA dealer (I have only been to Princeton for other things, and they seem ok). The pulley has nothing to do with it and the service guys in PA are driving cars with my same mods. Its just amazing, they can't seem to get rid of this issue. I would not care except the Jersey inspection is such a pain....

 

Has anyone changed out their own carbon canister and diagnostic pump?

 

Finally found and fixed my P0456 code. Dealer wanted to do a smoke test (no guarantees) for mass $$, no thanks.
The shop forman (good guy) gave me some directions to work in so I pulled the charcoal canister/vent pump from under the left rear wheel well and did some testing.
First test: vacuum on the charcoal tank (they can crack and leak). It held 12 lbs over night, not the problem.
Second test: vacuum on lines leading to engine control valve. All good.
Third test: vacuum on pump/solenoid assembly. Whoa! Some kinda leak!
The wiring harness plug for the pump/solenoid connects to the case thru three prongs that go thru the plastic. Inside, vacuum is maintained. When I disassembled the solenoid, I found what was left of some sealant that was supposed to make the connection airtight. It appeared to have just crumbled away, so I replaced it with a small dollop of clear RTV sealant (O2 sensor safe), re-assembled the whole thing and tested the next morning.
No leaks! Cleared the codes, and so far, no repeat. I'm liking this.

 

Update: been almost a week, and no reoccurance of the code.
That's a feelgood.

 

If you get time you should do a write up for what you've done. I don't want to get this problem or wish it on anybody else, but if i does happen to me, i want to be able to see how you did it.

 

After two years, I got a new charcoal canister, and voila, no more leak. Charcoal canister had a hairline crack.

 

Yup, according to the tech, cracks in the canister are the most common reason for the code. 'course, I invented bad luck, so it wasn't that simple.
Grillhands: I'll try to put something together for the fix, but it's all put back together, so the picture thing may be a little sparse. It's not a difficult fix, but a little intimidating when you first start prying (literally) things apart.

 

I'm very glad this issue was resolved, but it was very frustrating to have to go so long to get it repaired and have all my mods blamed. This is a common issue, yet took three smoke tests to find. I asked a long time ago if they'd replace this and the leak diagnostic pump and was ignored. But whatever. If you have a recurring P0456 - press to have the charcoal canister checked.

 

Amen, chaincoopers. The rest of the system seems to be relatively bulletproof, but the pump and canister gadgetry is pretty flimsy.

 

I've read the threads above and am trying to find the least expensive fix for the same fault code. I recently had my oil changed at my local dealership (Santa Clara, Ca.). Everything was fine and drove it home very satisfied. About 2 weeks later the Service Engine light came on and stayed on for a few days. Then is shut off for a 3 days and then came back on. A coworker who repairs cars on the side (but not MINIs) said he could connect his laptop to my car and find out the trouble code.

The code was P0456 and it read, "Evaporative emission system leak detected." We took a look at the o-ring/gasket on the fuel cap and noticed it was cracked. He suggested that might be the problem. But now I'm reading about charcoal canisters. Anyone help a starving writer/account manager with some suggestions? Thank you!

 

Hello all, new to the mini life as of 2 days ago, bought a 02 mini, as i was driving the car away from the sale i stopped to put gas in, and after 2 starts the cel comes on. The car is running like a champ, but still the light is on. Drove it from la to vegas back home, plenty of drive cycles still the light comes on. So i took it today to autozone and code was p0455 - large leak detected ? I went down to mini and replaced the gas cap, no luck after that with 4 drive cycles under my belt? Help im a little frustrated unable to track down, also the a/c light blinks on and off any thoughts HELP, please thanks chuck