2001 Hyundai Elantra "check engine light coming on?

Take it to your local auto parts store and ask them to read the trouble codes. Write them down and post them here and we will try to help.

Thank You. I have replaced Both 02 Sensors, and as of Tuesday, the "throttle position sensor"? The light has NOT come back on so far? But we shall see as the upcoming week approaches?

Are you randomly replacing parts? The codes will help narrow things down so that you don't waste money.

No, a freind used his Snap On Computer and it Originally showed a faulty Downstream 02 sensor? One week after installing it? The light came on again? I went ahead and installed a new Upstream sensor. One week later, the light came on Again? This time as i'm driving my daughters elantra, i got to see what she was describing with a Loss of power, (vehicle not accelerating a full capasity, even though i was pushing gas pedal all the way down? Then light came on again.

There may be another problem which is why I need the actual codes. Exhaust or vacuum leaks can show up as a bad 02 sensor. Misfires can also be a cause.

Alright Then. I will Update if the light comes back on this week? Thanks for your Repies

Btw, after the engine stammers and light appears, the engine goes back to regular running status.

I have a 01 Hyundai Elantra GLS with over 150,000 miles on it I bought it from a dealer because I was in desperate need of a car. I totaled my 2016 Dodge Journey in an accident (Hit a utility pole). The car is in pretty decent shape for its year and the engine runs great and has incredible pick up. My son was driving it in the rain and went through a deep puddle late at night and he said, " The car sputtered at first and the check engine light started flashing but then after pulling over and letting it sit for a moment the car smoothed out and ran normally but the engine light stays on constantly and won't go out... I've changed the o2 sensors but the light still stays on.