:confused: About a month ago the check engine light came on in my 2000 Hyundai Sonata. It has been to the garage 3 times since... So far the rear oxygen sensor has been replaced along with the Cad Converter and new Spark Plugs. After all this the Check Engine light remains on and while driving it feels like someone is applying the brakes, the cars slows down then takes off, and when I stop at lights most time the car will stall:(
Someone said maybe my fuel injector is dirty and so far I have spent $100.00 in fuel injector cleaner and still I have this problem:confused:
Please can anyone help me, thank you sooo much for any ideas that may be useful.

April:(

What code was thrown? Did you use a code reader to clear the old code?

Yes the first reading was for the Oxygen Sensor, second was for the Cad Converter, both cleared, then when I took it back the mechanic said it was still reading a prob between the cad converter and oxygen sensor (not sure what the reading was) and so it was this mechanic that said it could be a fuel prob and put in a $60 fuel injector kit.. the light went out for maybe 6hr. Then while driving came back on... I just don't understand why it feels like someone is applying breaks when I'm driving its scary... thanks for your help... guess I need to take it back to a garage yet again and get a new reading.

If you have the 6-cylinder engine, did you change the rear plugs? Did the mechanic clean the throttle body and ensure the Throttle Position Sensor is okay?

Hey TxGreaseMonkey,
It is a 4-cylinder engine, and No he did not check the throttle position sensor... Could this be my problem? If so could you maybe tell me where it is located and if there is any way to test it on my own? I know nothing of cars but I have a friend that knows a little and maybe they would look at it for me,thanks for your information I really appreciate it...

Buy a Haynes Manual for your particular car. The steps for testing the TPS should be in it. You'll need a multimeter. Also, check the idle rpm--it may be too low.