Pontiac Repair: 2001 grand am se 3.4l, rod bearing, mechanical failure

Question
Okay about three months ago I was accelerating on the ramp to get on the highway when I heard like a knocking or rattling noise, but I didn't pay it no attention. Then last month, I started my car up and there it was making the noise again. It get even louder when I'm driving, so I just stop driving it all together. So I took it to AutoZone and had them check it and it said it was the EGR valve, but I thought that had some to do with emissions. Then someone told me it was a rod bearing, what is that? I just want to know what do you think? I don't want to take it to a shop and they try to pull the wool over my eyes because I'm really low on funds so I need it fixed and not have it come back in like two months. I just need to know some before I take it in to a shop. Does it sound like the engine or the transmission? Oh yeah it does not pick up speed either. Thanks in advance for your time and help.

Answer
Hi Renae:

If the engine is making noise it's not an egr valve making the noise. If someone told you it's a rod bearing that is not good. That is a mechanical failure in the engine. If it lasck power that means 1 or more of the cylinders in not working propelry. if this car has a lot of miles on it I don't know if I wouold invest in getting it repaired. It' going to be 8 years old in another month. Weight the price of the repair. It's going to be expensive!