Check Engine - Off/on/off/on what..

[Corrosive]

Ok so first things first... I did a search.

My check engine light came on right after I did a fill up, I then tightened the cap and a day or 2 and about 80 miles later it went away. It was off for about 2 days, then all of a sudden it came back on. I have yet to tighten the cap again, but am now wondering if it could be anything else. I assumed that if it was something other than the gas cap then it would have never shut itself off like that. I will have time on wed to take it in, but just kinda want some peace of mind untill then. Is it possible that I just need a new gas cap bc the one I am using now just dosent seal as well as it did in the past? Any thoughts or ideas will help me out alot. Thanks,
-Mike

ps. If I take it to autozone and they check whats throwing the code, is there one that says gas cap or will that read something else?

[Joe_Black]

When you tightened the gas cap did it "click" several times?

It could be an anomalous error that threw in coincidence with your fill-up too.

If you go to get it read be sure to post and we'll look it up for the shop manual equivalent and go from there.

Also, you could disconnect your battery for about 30 minutes or so to reset the ECU and see if it returns.

[Corrosive]

Yes it clicked and I clicked it an un godly amount. I think thats what I am going to do. I will disconnect the battery over night and tighten even more then see if it comes back on. If so, then to get checked for sure.
Thanks,
-Mike

[JHarris1385]

I have had this same problem since I bought the VX only about 2 months ago......The check engine light will be off for a couple days and then just stay on for a couple days and somedays it will come on and off randomly through out the day.

But I am also expeirincing rough starts and low MPG (about 13-14mpg 70% hwy driving too.) Still cant figure out the problem..

[LittleBeast]

I am having the EXACT thing happening and Autozone keeps saying it is a P0440 fault code and the Isuzu shop is still maintaining that it is probably just the gas cap being loose... Doing a search on here brings up some interesting things but none really give a definitive answer. I have already had my EGR replaced and just had the tubes connecting to it all cleaned 2 weeks ago, but maybe something is loose. It gave me the code only for a couple of days before the EGR and tube cleaning, but it has come back now. Other treads:
http://www.vehicross.info/forums/sho...&highlight=440
http://www.vehicross.info/forums/sho...&highlight=440
Hope that helps a little as I am still trying to be completely rid of this problem myself.
In Christ,
Ryan

[Corrosive]

I have to admit that my VX has a somewhat of a rough startup and my gas milage is the same as yours, but then again I think that the gas milage is normal.

Small update ---- I didnt mess with the cap at all and today it turned off while I was on my way to work. I didnt pull the battery or anything, it just turned off on its own.

I still plan to take it in to get an oil change/check fluids/and brakes on wed so we just might find out something that is wrong.

-Mike

Beast... do you think it may be the weather (remember that we live in the same city)? Mine has only started doing this once it started to get colder?