M 2002 Hundai Elantra wont accelerate past 20 MPH but the RPM goes to 4 or 6 what can be the problem i was thinking transmission but....
You may be building excessive back pressure due to a clogged up catalytic converter on your exhaust system. Can you hear any rattling under the car?
I haven't then again my car makes lots of noise due to an accident i had and there's something under the car i need to get fixed, so i cant tell the difference. sorry
ohh and the check enginee is on too
If you can get it to an auto parts store, they can retrieve the codes for you with an OBD-II Scanner. That would help us a lot to be able to diagnose the problem. Once you get the codes, post them on here in a new thread and we can get you some help.
Thank You Mark :)