I have a 2007 vw gti that has 355k miles, it was running perfectly fine til last night after filling up it started to stumble while accelerating thought it was bad gas. I got it up to highway speeds and it held speed fine but when i came to a stop was running extremely rough. I stopped the car shut it off and after 30 minutes the car started up and it is running perfectly fine today.
There was no strange noises, no smoke however there was a strong smell of oil burning when it was running poorly but as stated no smoke in the engine bay or out exhaust.
The other strange thing is when it was running like crap and could barely accelerate i managed 35 mpg over 90 miles driven.
I got the codes read today and all that was read was p0016 p2181 and a code for oxygen sensor.
Like I said car is running perfectly fine today. Just trying to figure what direction i go and where to look first to make sure i dont make it worse