Morning all.
I have been working on a 2004 cherokee 4.0 for a friend. It has given her the p0455 large leak code.I have smoke tested the system, found and fixed many leaks in the hoses and replaced fuel cap. The check engine light would stay off for 2 or 3 days then come on. Last attempt to fix, it stayed off for over a week and almost 300 miles. Unfortunately it has returned. (after she refueled it ) The only odd things are that the fill tube is missing the little flapper thingy and when I smoke test it, I can hear air escaping from the big vent tube. ( I am guessing that is what it is. It has a plastic cap that has 4 prongs that go in the tube, not an air tight plug) So i guess my questions are, should the system be completely air tight, and would not having the flap in the fill tube affect it. Thanks for any help.
I have been working on a 2004 cherokee 4.0 for a friend. It has given her the p0455 large leak code.I have smoke tested the system, found and fixed many leaks in the hoses and replaced fuel cap. The check engine light would stay off for 2 or 3 days then come on. Last attempt to fix, it stayed off for over a week and almost 300 miles. Unfortunately it has returned. (after she refueled it ) The only odd things are that the fill tube is missing the little flapper thingy and when I smoke test it, I can hear air escaping from the big vent tube. ( I am guessing that is what it is. It has a plastic cap that has 4 prongs that go in the tube, not an air tight plug) So i guess my questions are, should the system be completely air tight, and would not having the flap in the fill tube affect it. Thanks for any help.
