[mirracobmx40]

So before I start, I'm new to this forum but had an e46 and was on e46fanatics previously. Now that I have a 335 I am new to turbo bmws so I have some questions and want to explain what has been done to the car so you all can have a better understanding. I've searched for this answer but didn't find a solid thread.

I have a full bolt on 335 (n54) with catless downpipes and methanol injection + upgraded injectors. I previously had a tune on it (MHD) but no longer have the android phone or the login for the google play account I bought the licenses on (my fault, I'll buy a new license soon). I took the car to the dealer for multiple recalls while I had the tune and I guess they re-flashed the ECU to a stock tune? Ever since I've gotten multiple emissions/SES codes multiple times throughout a single drive.

Since they're all codes for o2 sensors and cats, I've simply cleared the codes whenever they pop up and continue to drive the car. it's annoying because it's a daily practice, but it's a temp solution until I tune again. This solution kind of works but sometimes I see a ton of white smoke coming out of the driver side tailpipe. Nothing out of the passenger side. Clear the codes, start the engine, no smoke, good to go. Until yesterday. No engine light, read codes anyway, nothing. Smoking like crazy. Floor it down the street thinking I could clear up the smoke and left a cloud of smoke behind me. Then the car was back to normal. Before this I've only seen the smoke with an engine code.

Is there something wrong with the car? And if I continue to just clear the emissions codes and drive it as normal (as annoying as it is) will/is it causing damage to the engine? I just passed 70k on original turbos (I think) no wastegate rattle and no weird idle or oil leaks.

And for the simple solution of "just buy another MHD license" I just graduated college so the money for that is on the bottom of the totem pole at the moment.

Sorry for the long post, but any insight would be amazing.

[MooreBoost]

Any perceived correlation between clearing the codes and getting rid of the smoke is almost certainly a coincidence.

You're not hurting anything by clearing the codes, but you do likely have an oil leak somewhere; perhaps turbo seals.

[mirracobmx40]

Originally Posted by MooreBoost

Any perceived correlation between clearing the codes and getting rid of the smoke is almost certainly a coincidence.

You're not hurting anything by clearing the codes, but you do likely have an oil leak somewhere; perhaps turbo seals.

Could it be the oil filter housing gasket? I haven't checked mine but I know that's a known issue for leaks...

[kwatkins12]

Originally Posted by mirracobmx40

Could it be the oil filter housing gasket? I haven't checked mine but I know that's a known issue for leaks...

Just replaced the OFHG on my FBO car and before doing it there was no smoke. On mine and I'm assuming most when the OFHG leaks it drips down the front of the engine, that's also how it can get onto the belt.

[Glando7]

Originally Posted by kwatkins12

Just replaced the OFHG on my FBO car and before doing it there was no smoke. On mine and I'm assuming most when the OFHG leaks it drips down the front of the engine, that's also how it can get onto the belt.

More than likely turbo seals. I'm my experience at about 80k Id get a darker gray smoke smoke out the tail pipes ALOT + O2 sensor codes. Prior to I was running fbo stock turbo with serious waste rattle. Was constantly adding oil every couple thousand miles. Bout 12k miles later the smoke color changed. It's now a whiteish/light blue smoke and I was to the point where I was adding coolant. So.... Coolant and oil leaking through. Needless to say the car has been parked waiting for some new parts. It's drivable but embarrassingly drivable. On a MHD bef with about 30% ethanol I drove it straight to and from the dyno and made 368whp 395wtq smoking like a chimney.

Inspect your turbos if you can. It sounds like the issue I have. Your mileage may vary.

[Jerain]

So you have no money for just the MHD license but you bought a N54.

[MooreBoost]

Originally Posted by mirracobmx40

Could it be the oil filter housing gasket? I haven't checked mine but I know that's a known issue for leaks...

You might have that issue but it's not causing the smoke.

The smoke from your exhaust is indicative that oil is being burned somehow. Either leaky turbo seals or less likely, valve stem seals.

[mirracobmx40]

Originally Posted by MooreBoost

You might have that issue but it's not causing the smoke.

The smoke from your exhaust is indicative that oil is being burned somehow. Either leaky turbo seals or less likely, valve stem seals.

You mentioned that the smoke and code clearing is almost purely coincidental, but I've been driving the car like this for over a month now. Without fail, whenever I clear the codes and start the car back up, there is no smoke at all.

There are a number of codes I get like p2c6c, 2c7f and a few others which just relate to lambda probe warnings but the one that caught my attention was p114d (2 codes, one stored and one pending). This is lean fuel trim bank 2 after catalyst. The engine thinks there is too much air so it dumps more fuel in. Could the smoke be excess fuel just being burned off?

It doesn't look like thick white smoke. More like the normal smoke you see coming out of tail pipes on all cars in the winter, except a lot more of it. And I'm in a warm climate so it's not just cold weather and normal exhaust I'm seeing here.

[mweisdorfer]

Originally Posted by mirracobmx40

You mentioned that the smoke and code clearing is almost purely coincidental, but I've been driving the car like this for over a month now. Without fail, whenever I clear the codes and start the car back up, there is no smoke at all.

There are a number of codes I get like p2c6c, 2c7f and a few others which just relate to lambda probe warnings but the one that caught my attention was p114d (2 codes, one stored and one pending). This is lean fuel trim bank 2 after catalyst. The engine thinks there is too much air so it dumps more fuel in. Could the smoke be excess fuel just being burned off?

It doesn't look like thick white smoke. More like the normal smoke you see coming out of tail pipes on all cars in the winter, except a lot more of it. And I'm in a warm climate so it's not just cold weather and normal exhaust I'm seeing here.

How old are your post cat o2 sensors? They monitor fuel trims

[mirracobmx40]

Not sure. I didn't install the exhaust system on the car. The previous owner did. He had the car for less than a year though and I've had it for about 8/9 months now.

[type-dRew]

Own the wrong car if $150 is a stretch