Rough Running 1600-2000 rpm at Light Throttle Regardless of Gear

[F22Chris]

Haha! I say it's closed still. I recently cleaned mine out for emissions, and there was no possible way gasses could get back into the intake. The ports were clogged shut, and the valve itself was caked in carbon. The bowl-like valley under the EGR valve was covered in about a half inch of carbon, too. I had no CEL. I think it checks vacuum, but I could be wrong. It's not like we can get a p0401.

[Fleetw00d]

I'm pretty sure the device on the top of the valve is a position sensor, so if it connected to vacuum and operating correctly, it will give the proper position feedback to the ECU, even if the ports are clogged and nothing is getting to the manifold. Mine must be opening for it to affect the engine, almost seems like it opens/closes repeatedly very quickly. If I get back from Cleveland early enough tomorrow I'll have some time to do some more troubleshooting.

[F22Chris]

Sounds good, you are very through with your projects. Im in for what you post up, do, and what you find.

[Fleetw00d]

I teed in a vacuum pump with gage, then drove it. Vacuum only pulls a few inches of mercury when the valve is activated, no wavering of the vacuum gage, but I did have about 6 feet of tubing to the gage. I could duplicate the rough running using the pump. Didn't get to do much else. The car is going to FL with my son to school tomorrow. I tried to clean the EGR passages today, but the drill punched through one plug then through the smaller port opening below (haste makes waste). I fashioned a block off plate for under the valve so it runs smooth without EGR and won't throw a code. I have a couple spare A6 runners; I'll take my time and clean one of those up for when the car is back at Christmas.