2002 Sonata LX V6 - RPM drops when I push the gas, driving bucking, shifting erratic
 

Hi, I have a 2002 Hyundai Sonata V6 LX. While driving the engine RPM decreases in speed and power, then kinda comes back. I push the gas and the RPM drops and goes up erratically, kinda feels like the transmission has problems shifting during the problem, engine revs and the car don't go forward sometimes. It has 82,000 miles on it, I bought it with 75,000 on it. The general maintenance seems to up to par. I'm not sure if the timing belt has been replaced, but that squeaks at times, and looks like it may need replacement. Any help would be great on this.

You can't see the timing belt by looking under the hood, it's behind a cover. You're probably talking about the accessory belts. If the accessory belts are old and worn looking, then chances are you have the original timing belt, which is bad.

One of the first questions I ask when looking at a used car is:

When was the timing belt replaced?

Your belt was due at 60K, and if you don't know for sure, you need to change it. If it breaks, your motor is gone, you need a new motor.

As for the RPM problem... Is there a check engine light?

The check engine light came on and off a couple times over the past couple months. Its not on at this point with this current problem. BTW is there a way I can check the timing belt? What would I look for in a bad or good belt?

You need a code scan. Take it to Autozone for a free scan, tell them the "check engine" light is on. Write down ALL codes and report them here in this thread.

You can check the timing belt by removing the top of the timing belt cover. However sounds like you are WAY overdue, so just go ahead and change it. You don't sound too up on timing belts, so I recommend you take it someplace and have it done, it's not a job for a novice.

Ok. I'm gonna look into this further tomorrow, also the check engine light is not on, can I still get the code scan done?

Yes, there should still be codes stored in memory. Don't let the Autozone guy diagnose the codes and sell you parts just yet.

Ok thanks.

Ill be getting the codes in just a few days. Then we can go from there. : >

My 2000 GLS V6 was having the same issues,turned out to be the cat converter bank 2. the easiest way to find out is to take of the first Co2 sensor and take it for a short ride you should feel a huge improvement, and yes it will be noisy but its any cheap and easy test to find out if your cats are burned out and bogging down the acceleration :)