Thank you so much guys!!! For now Itightened the gas cap and reset the computer. I drove couple of miles and so far the "check engine" is off. I will keep you posted. Thank you for your help. I didn't expect so much help in such a short time. You are really great!

 

Another 25 miles today and still no "check engine" light.
By the way another question.I read somewhere on the internet that in order to reset the computer, instead of disconnecting the battery one can also follow certain procedure ( park, RPM to over 6000/min, R,N,D,3,1 and back to park, etc). When my Neon was on park I was not able to get more RPM than 4500.Is it blocked somehow or is my car a lemon?
Oooops. I got the answer. because it is Automatic transmission it is electronically blocked to save the engine.

 

don't ever do what you read... think of your car computer like your modem. need to shut down the power to reset it.

 

If P0440 problem still exists when can I expect to come backto my dashboard.I've heard 200-300 miles but I don't have any experience with that. I've never had "check engine" on any of my previous cars.

 

Check out the pic i posted of the service manual... Most of it you probably won't understand because its instructions for the DRBIII tool.

Note the "When Monitored" and "Set Condition" areas at the top. In a nutshell, as long as you have more than 12% of gas in your tank it would have already checked and you would have seen the light.

remember, at least 3 clicks on the gas cap when putting back on.

 

What he said. I picked up a set of Bosch Platinum Plus then read the FAQs on a couple Neon forums and took em' back and got NGK Iridiums instead. They're suppose to work pretty good but a fresh set of Champions are suppose to be ok too.

 

i also had bosch platinums in my car before and they made my car run very rough. I think those were even the reason that my ignition coil fried. I now have NGK Iridium plugs and they haven't given me any problems. As for your evap code, if it comes back up, try to buy a new gas cap, now if that doesn't work, more than likely it is a cracked hose somewhere to the left of your rear passenger wheel. That is what happened to me when i had a similar code. No code ever since I got the hose replaced!!

 

With gas prices the way they are you should probably by a locking cap anyway. This may just the reason you need to pick one up.

 

+1 The hoses he's talking about are the vapor hoses off the evap canister, they are just right of the gas tank and problems with them cracking are very common.If the light comes on I could almost guarantee you that those are the problem. They are a special type of hose, but they can be replaced with fuel line hose as long as you can get them to fit nice and tight.(regular vac hose will deteriorate)