I own a 2004 Sonata 34000 miles on it 2.8 engine. Today the check engine light came on while driving. I checked all fluids and the engine doesn't fill any different while driving (still smooth). What area should I check next? Or is this a computer hookup thing to figure out what it is?

 

i have the same problen with my accent.... i went to check it out on the OBDII thingy and it said i had engine misfires and an unknown trouble code of P2800.... i tuned it up and go back on the OBDII thingy and the misfires were gone and now i just have the unknown trouble code of P2800... its an unknow trouble code that no one has been able to help me with.... but my car runs fine... and my MIL status is on still

 

Stop at Autozone, they will read your codes and reset them for free. Here's a link to find out what the codes are:

http://www.obd-codes.com/trouble_codes/index.php

 

i went to autozone but the P2800 doesnt go away

 

im sorry... that trouble code was P1128

 

steelergalwv- If you're in the U.S., go to AutoZone and have them read the codes. Then take it to the dealer and let them fix the car; it's still under warrnty.

The only reason I say read them first is that if the dealer has problems fixing it, knowing the code yourself can help you when you're talking to the technician- it's harder for him to B.S. you.

 

Thanks everyone. I had it hooked up this morning and it was the gas cap sensor. Apparently I have one of the "new sensors" on the newer cars that sends engine light error if your gas cap isn't closed completely, this is to make sure no gas fumes escapes into the ozone. IF you own a Hyundai PLEASE turn your gas cap at least 3 clicks after you are done fueling. I have heard of this before on some show or in an article. Now I have it[:@]. IF your engine light does come on the only way to get it reset is to have it hooked up and the that person should be able toreset it. (sorry I don't have the code but might be able to find out for you)

 

The light came back on today. I went to the Dealer ship today (since it is still under warranty) They hooked it up and it had soemthing to do with the E-value? Filter? I want to say it sounds like a fuel filter. It is located in front of the fuel tank and had some dirt or stuff clogging flow. They took it off and cleaned it out and put it back on. NOTICE I said they put it back on. NOT put a NEW one on.. hahahaha. They said if the comes on again they wold put a NEW one on it then. I guess we will see.

 

Heh. 3 clicks. They told me the same thing. I scoffed at the notion that there was something special about 3 clicks. But whether there is some sound technical reason or it's just voodoo, it does seem to help!

I actually had a similar problem on my Elantra... the same kind of thing- at first they said gas cap, than a bad Purge Valve in the Evap system, then a check valve, then eventually they replaced an O2 sensor. Note that when my dealer diagnosed one of the bad valves, they didn't have one in stock so the cleaned the one I had, put it back on the car, BUT they ordered a new one and installed it when it came in. You're still well within the warranty period, but KEEP THE RECEIPTS of the work that's been peformed. If this ends up playing out like mine did, it may take several more visits to the dealer to get it fixed once and for all. (I think it took me 4 or 5 visits over about 6 months). By saving the receipts, you can remind the dealer about the previous issues and what was done, so they're not starting from scratch.

Apparently Evap System problems are kind of tough to diagnose. My dealer followed the troubleshooting chart exactly, but it took a few tries to get to the real problem. I was pretty frustrated while all this was going on, but I haven't had any problems for a long time now so I'm pretty sure they finally got it fixed. But understand that this is kind of a tricky system to diagnose; the codes don't necessarily point to the solution, just a list of things that *might* be wrong.

Even though it took several tries, my dealer worked with me in a very friendly and efficient manner; I suggest that if you have to take this back for the same problem, bear in mind that if it isn't fixed right the first time it isn't necessarily the dealer's fault. And also know that your car is still basically sound, it just might have one or two little parts that aren't working right. Be patient but persistent and things will work out.

One last thing: One cause of Evap System problems is over-filling the gas tank. Make sure you never fill past the first time the pump shuts off.