Smoking and low rpm stumbling/misfire help

[BoostinLI]

Hey guys, so this is my situation. I was driving on a nice stretch of road (spirited) on e85 ots w/ flexfuel kit when suddenly I felt the engine start to misfire with acceleration followed by horrible whitish smoke. Car literally burned half a tank in less than 10 miles, with the driverside muffler tip soaking wet.. No drivetrain error, but just code for bank 1-2 too rich. I got the car to a trusted shop and they state injectors leaking, so had those replaced along with new spark plugs. So car started up quickly and idle good after few revs, but when I drive it still smokes a fair amount (not nearly as bad). I was told to expect some smoke because of fuel in exhaust, but driving back home, the car between 1500-3000rpm its breaking up pretty bad, still better than before, but if i accelerate and take the rpms up it feels back to normal. Also, the code for rich Bank popped up on the way back.

Any thoughts? Can bad o2 sensor cause this issue with misfire and smoke? Is e85 in exhaust system the reason for smoke even after maybe 25 minute drive?
Thanks guys

[TopJimmy]

The O2 sensor might be fouled. Give it a good long drive and see if it burns clean. Mine cleared up after my injector failure. I've seen others not have luck burning off the fuel fouling and needed a new sensor.

Make sure to change your oil twice in a row so you get all the E85 out of your oil. Remember the oil cooler holds a quart, and doesn't drain during a regular dump change. You would need to open the 2 hex caps on top of the oil thermostat and suck the oil from down the cooler lines. If you do the suck-out then you only need 1 oil change.

[BoostinLI]

Originally Posted by TopJimmy

The O2 sensor might be fouled. Give it a good long drive and see if it burns clean. Mine cleared up after my injector failure. I've seen others not have luck burning off the fuel fouling and needed a new sensor.

Make sure to change your oil twice in a row so you get all the E85 out of your oil. Remember the oil cooler holds a quart, and doesn't drain during a regular dump change. You would need to open the 2 hex caps on top of the oil thermostat and suck the oil from down the cooler lines. If you do the suck-out then you only need 1 oil change.

Hey Jimmy thanks for the quick response. After driving the car some more, all smoke is now gone for the most part. Right now just waiting for the o2 sensors from BMW as there seems to be no aftermarket for the upstream o2s 😒😒. Is this a difficult job in your opinion?

[TopJimmy]

Originally Posted by cesarlcase

Hey Jimmy thanks for the quick response. After driving the car some more, all smoke is now gone for the most part. Right now just waiting for the o2 sensors from BMW as there seems to be no aftermarket for the upstream o2s 😒😒. Is this a difficult job in your opinion?

You need to do the effort for swapping both downpipes, so you can get to the sensors. It's not a hard job, just long on your back. It's easier when you reuse your old v-bands, but you do need a new pair of turbo gaskets and down pipe gaskets.

[BoostinLI]

I figured instead of starting a new thread I'd continue here. So as of now, new fuel injectors and o2 sensors have been installed, car runs great in that regard. The issue I'm still having now is the car continues to smoke, not nearly as bad as it did when the injectors failed but, seems once I start driving and come to a stop the odor of burnt oil fills the cabin. I was able to witness what appeared to be bluish smoke (not 100%) come from the tailpipes tonight. I have a BMS catch can in place which I will check tomorrow, also will pull the plate off tomorrow to see if there is a leak with UV light. Car has about 37k. Oil level still full. Is it possible that I'm still burning residual carbon build up that e85 may have broken off in the exhaust or is this something else? Hate to see this awesome car in this condition.