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Code P455 in 01 XJ. What should I do?


NAXJA Forum User
2001 Jeep XJ AW4 w/ 4.0 and 70k miles. The little transmission looking light came on and I went to Schucks and had them pull the code. Came up with P 455, and they told me it has something to do with a leak in the emissions system.

It smells like gas sometimes too.

What should I look at first?
Not sure, but on my XJ when I smell gas ther first response is to check the o-rings on the fuel injectors. Not sure how that would tie into the transmission light and emissions. I guess if you were running to rich or something it might cause the code and smell.
Make sure your gas cap is tight. I don't know which code is set when it isn't, but the check engine light comes on and I presume, a code is set.

Gas cap is on secure and tight (already checked).

The "Check Engine" light isnt on, but the one with the picture of what I assume to be a transmission was on. The print out Schucks gave me said it might have something to do with a charcol container that collects fuel vapors in the gas tank. Does that sound familar to anyone?
x2 on the Gas Cap.
"P0455XX Evaporative Emission Control System Leak Detected (gross leak)"
When did the light come on? (after you filled up the tank?)
Could be that the cap seal is leaking.
I would make another run to the Autozoo, get a new cap and have them cleared the codes.
Did they pull/check for any trany codes?
If not, go check with them.
I'm not aware of a transmission warning light on the dash. I looked in my owners manual and non is listed. The check engine light is located immediately to the right of the trip reset button. If you're sure the gas cap is ok, then I would check all the hoses associated with the evaporative system.
There will be a hose from the tank to the charcoal canister, from there to the engine compartment where the solenoid operated purge valve is located. During the purge cycle, the solenoid is pulsed rapidly, switching the charcoal canister to the intake manifold where the fumes are burned. When the purge cycle is going on you will hear a popping or clicking noise coming from behind the glove box. The purging is determined by the the main computer based on driving conditions, such as miles,speed, number of starts,etc. The purging valve is located in the engine compartment, close to the firewall, on the passenger side.

mine does the same thing once in awhile...its always the gas cap.
tighten it and after about 4 or 5 starts the light goes off.
i have an 00 and there is no trans light in my dash, so that's got me baffeled!?! hope you finsd a solution.