Purge Control valve and Emmision Error Codes

[NoFlyZone]

P0441 or 16825 along with the lean bank 1 code is keeping me from smogging the car.

2000 1.8TQ 220 plus K miles.
replaced all the vacuum lines.
replaced the rubber elbows that descend to the 710N diverter valve and checked valve operation. Replaced 02 on the upstream end of the cat. Can a bad purge valve create the lean condition. Where are the purge valve(s) located and how many to replace?

[walky_talky20]

Is the lean code additive or multiplicative? Actual codes would help here.

Anyway, the most common cause for lean codes is a dirty or faulty Mass Air Flow (MAF) sensor. If you have vag-com, you can log it to be sure. Otherwise you can try cleaning it or replacing it.

[NoFlyZone]

About the only thing I haven't screwed with is the MAF. I'll give it a good cleaning as I do use a K&N that could gunk it up. But, this emmision code 16825 EVAP Emission Control Sys is not one I've seen before. I'm not seeing the relationship between this and the MAF. I cleared the codes and all was well for 2 days, then the light, followed by more tinkering. I'll try to post the actual codes.

[BlackBirdSR71]

Yes, a bad Purge valve ( I assume you're talking about the N80 valve. Evaporative Canister Purge Valve ) can definitely cause a lean condition.

Overfilling fuel tank, can cause the N80 valve to fail. There is a VW/Audi TSB on this exact issue.

[walky_talky20]

I don't think the lean code can be caused solely by the purge valve. The evap vapor does add a slight enrichment to the mixture, but a lean code won't trip till the o2 sensor has to enrich by over 15%. I'll bet his K&N has dirtied the MAF to cause the lean code and the evap code is a separate issue. Just IMO.