2001 Cherokee Engine Light advice

My 2001 Cherokee Sport has otherwise been a good car, but shortly after buying it used a couple of years ago, the check engine light came on. I took it back to the dealer and the shop manager told me it was due to a loose gas cap (or something about the gas cap) and no big deal unless the light started blinking. So he turned it off and a day later it came back on again. We took him at his word and just ignored the light.

Now, however, we are trying to sell it and figure it's best that the light goes out. Staying on would rightfully scare off many customers I'm thinking.

I took it to Advance Auto and an old friend who works there hooked it up to the computer. He got the following readings:

DTC (Codes)

PO455
EVAP Emission
Cnotrol System
Leak (Large)

DTC Pending (Codes)

PO442
EVAP Emission
Control System
Leak (Small)

So he said it's probably a vacuum hose leak and a good way to find it is to spray carb cleaner on each hose and listen for the engine to idle faster. I did this to every hose I could locate and got nothing. Any suggestions for what I can do to get this light off for good?

Thanks in advance.

If he said it was a loose gas cap, it could also mean that it wast tight, so the gas cap might be bad. You might look into that..

That would be a cheap remedy if it worked. I'll give it a try since it's quick, cheap, and easy to do.

Any other ideas guys? Could this be a more serious problem? Would the gas cap being loose register on the computer the way I listed it above?

I have the same problem with my 01 and was given the same advice.

I posted earlier and you can Alohabra's response. I did the connection to the battery once and that turned off the light. All I had to re-set was the clock. All the radio stations stayed the same. The light came back on again two days after I "re-set" it.

I am going to have the gas cap checked.

I likewise am thinking of selling and no one would want to buy a headache like that after it's sold. My mechanic said it be a $300 or more fix to find and fix the leak.

I will let you know I find out. Please do ths same.

bmwgolfguy, I will let you know what happens with mine. I'm taking it to a mechanic tomorrow morning. I sure hope it doesn't end up being as expensive as you say.

The shame of it is that it is only an emissions system problem. From all that I have read on the subject, the system is very sensitive and prone to failures such as this. After all, my light has been on since around the 60k mile mark. That seems pretty young in it's life for a failure like this.

I found an article explaining how the EVAP system works if anyone is interested.

http://autorepair.about.com/library/a/1h/bl010h.htm

thaks for the reply greg m. I am going to do the gas cap thing and hopefully it will take care of it.

I will keep you posted as well.

The new gas cap didn't help. The light is still on. The mechanic I go to is purchasing a machine that will help identify the source of the leak and fix.

Again, I will keep you posted.