Oil smoke on startup, oil drops coming out the exhaust?

[gnarjunkie]

Hoping to find good news here, but not expecting it

2017 BRZ track car. ~45k miles. Supercharged with Edelbrock kit, mild tune making 250whp.

Car started throwing codes two events ago. Started with P0171, then P0420, then P0141. All codes related to the o2 sensor. Also started smelling gas randomly. Figured the o2 sensor was going bad and the car was running rich. Everything drove normally.

Replaced the upstream sensor, smell of gas went away. Car continued to drive great.

Then at the end of the last autox event it shot quite a large cloud of smoke when I started it up for afternoon runs. No smoke on revs, so we ran the last few runs. Smoked again when starting it up to drive home after trophies, but less so. Still no smoke when revving. Popped a P0171 on the drive home after driving great all day.

Left town early the next morning for a wedding, so the car sat for 5 days or so. Started it up when I got back (yesterday), more blue smoke. Still nothing on revs. Didn't drive it, just shut it off.

Today started it again, more blue smoke. This time it's spitting what seems to be little drops of oil out the exhaust and it smokes a smaller amount when revving along with spitting more drops.

I'd originally thought maybe it was just blowby that had pooled in the intake between autox runs (especially since the oil was a bit overfilled), but with it now smoking every time it's started, I'm starting to think it's something worse.

Any thoughts, ideas, or experiences to share?

[alphasaur]

catless? I'd be concerned for ring lands but hopefully could be something less ominous

[DarkPira7e]

Make sure to feel whatever is coming out of the exhaust, make sure it's not just sooty condensate. If it's oil, it will be extremely easy to tell.

Why not pull the Edelbrock air intake tube and see if it's pulling oil through the crank case vacuum?

[gnarjunkie]

Originally Posted by alphasaur

catless? I'd be concerned for ring lands but hopefully could be something less ominous

Catless headers, but still retains midpipe cat. Ringlands are also my chief concern.

Originally Posted by DarkPira7e

Make sure to feel whatever is coming out of the exhaust, make sure it's not just sooty condensate. If it's oil, it will be extremely easy to tell.

Why not pull the Edelbrock air intake tube and see if it's pulling oil through the crank case vacuum?

That's a good idea. I did think maybe I jumped too fast to thinking the drops were oil based on the smoke. I did swipe my hand through the drops on the ground... sure seemed oily.

Pulling the intake and checking for oil was my original plan -- and I'm still going to do that tomorrow -- but the fact that it's smoking after just sitting without being driven is making me discount the blowby theory.

Especially since this car has never had blowby issues running 20 minute track sessions... seems pretty odd that it would suddenly start having massive amounts after an autocross.