Hey guys.
I have searched here and everywhere to see if I could find a clue to my problem .
I have a 2010 MS3 with 71000 miles. It recently threw a code for the secondary O2 sensor. Then I noticed the exhaust was smoking, but only under a specific condition. If I take my foot off the gas to slow down, when I accelerate again, I get a fair amount of blueish smoke from the exhaust. It does not smoke at startup, but after running a long time, I will get some at idle.
Startup is rough and will sometimes give me a multiple misfire code. After warm up though, there is no rough idle or surging.
From my research I see it could be valve seals, rings, turbo, or pcv. I will be doing a compression test and changing spark plugs soon and I will change the pcv too, but it looks like a real pain in the ass on this car. I was hoping someone would have an idea.
Thanks+