[mcormier42]

I see I'm not alone in dealing with Limp Mode(the car not me). 99.5 jetta. I'm not as far along in trying to fix it as a few of the other posts I've seen but something I've noticed with mine is when it's wet or really humid out, the issues temporarily go away. I'm hoping mine is just a vac line issue but either way I'm confident that with digging around through these threads I'll be able to fix it.

As for codes, Autozone isn't much help and you don't want to pay $50 at the dealership. From what I understand, Advanced or Foreign Auto(or whatever its name now is) typically has the upgraded comp systems to better diagnose VW problems. Will be trying that this afternoon

 

[chittychittybangbang]

Yes, on your 99.5 it's time to do some catch up maintenance if you want the car to run well. I don't know why humidity would cause limp to go away. It's not like the vac lines swell in response to moisture. If you're stuck, please post a follow up.