I just did the LIM gasket and the valve cover gaskets on my '99 grand prix gtp. Ever since I finished I keep getting the P0401 code(insufficient EGR (exhaust gas recirculation) flow). Any idea where to start. There where no codes before I did the LIM gasket.

Did you bolt the EGR tube back up to the LIM under the TB?

Plug the sensor back in to the EGR valve?

Those are the only 2 things you would have had to remove to do the LIM gaskets, I would check there.

Yes and yes, any other ideas?

Did the tube crack when you pulled the end out of the lim? If not it may just be coincidence that the valve carboned up and is sticking now.

Did you remove the egr completely or just pull the end out when doing the gaskets?

I just pulled the hose out of the intake.

any ideas?

it can only be a few things.

1) sensor is not plugged in
2) tube is cracked and leaking gases
3) valve is carbon'ed up and stuck

Since you've already checked the tube and plug you're best off to go on ClubGP and see if someone has an EGR valve for sale. I just sold a spare one I had last week or I'd send it you.