insufficient flow to ERG valve. Is this the map sensor?

Its not going to make noise from a bad map sensor what are the exact code numbers you have?Also sounds like you have a leak somewhere.

the port the erg valve plugs into was completely clogged. Mechanic is going to clean it out, and reset the computer if the code returns, do you think I should have him run a smoke test to look for a vacuum leak? Thanks your that fast response!

Your still keeping me in suspense with the actual code number no code description which i asked for in my last response.

sorry about that, code: P0401. The computers been reset and the code has not come back. But it is still making a starnge noise when I try to accelerate hard and isn't accelerating fast. I called the mechanic back to ask if he had any ideas, he said there was a O2 senor code that had been in the memory...but that doesn't seem right.

The P0401 would be caused by the clogged egr port.He isnt the same guy that replaced your egr valve without checking the egr port for being clogged is he?Also the o2 sensor isnt going to make a funny noise when excellerating.So is the engine totally bogging down?

no its not the same guy that replaced the egr valve. I just drove it around and the acceleration seems normal. It does make a grinding noise when I give it some extra gas. If I take it easy I don't hear the noise, but if I'm getting on the highway its there, right as I hit the gas peddle, but is gone before I pull my foot up. Sounds likes its coming from the front of the car. Grinding noise.

Transmission or engine is the grinding noise coming from?

took it to a friend, the noise was hard to hear, but it sounds like its coming from the engine, said he thinks it the heat shield vibrating. does this happen more during acceleration?

Yes it would because there would be more vibration and engine movement.

i have a similar problem but i get code p0440 on 99 alero

You have a older model with a totally different code its no where near similar.Please post a new question for your concern thanks in advance.