PO 440 - Code

[ThunderChicken]

Thanks for the response. I checked the gas cap last week when I took it in and it doesn't seem to be the problem. I thought if it were the EGR sensor it would show up on the code read out AGAIN.

It did code out the EGR and then it stopped and started coding other things instead.
My mechanic cleaned the EGR but we never replaced it. Could it need replaced now that I had the intake gaskets replaced.

I'm at a loss on this.

[Dare2Dream]

My knowledge is limited but i know one cause of the surging revs is an air leak. I meant to say check for air leaks around the EGR, e.g. a loose/broken bolt or a bad gasket. I don't know if a bad EGR will cause this but a leak around the EGR will.

As I said, if you notice the sound similar to holding a card in the spokes of a bike, then you have a leak. If not, then I have no idea what the problem is. I wouldn't change the EGR unless you knew it is the EGR.

So you replaced the intake gaskets? Was that the original diagnosis by the mechanic?

Anyone else have ideas?

[Hotsauce]

Thats not the code that the egr throws, the egr will throw a false code of low o2 sensor voltage.

I had surging once, but it threw no code. The cause turned out to be the throttle body gasket damaged by where the idle air bypass is.

John C.