Lots of smoke and oil loss

My car has been smoking a bit on startup for a week now (not huge billows, just puffs and then stops). Hard to remove the oil cap while engine is running, so I ordered a new air-oil separator for replacement this weekend. For my 120k mile service, I just replaced sparkplugs 2 weeks ago and car has been running otherwise just fine. Driving home just now and engine starts to flutter. Low oil pressure light flicks on and then goes off. I look in mirrors and there's a puff of smoke, then a light stream. Suddenly huge amounts of smoke (white/grey) billow out the back of the car and I think my car is on fire. Find a place to pull over a block of so later after coasting down the road and shut the engine off. Push car last block to my garage and pulled out the mini OBD2 chip to see what's wrong. There is a sulfur-like smell, and when I checked the oil, it was very very very low. (I just topped the car off this morning). Confirmed diagnostic codes: P0171 System Too Lean P0300 Random/Multiple Cylinder Misfire Detected P0306 Cylinder 6 Misfire Detected P030 Cylinder 3 Misfire Detected P0002 Fuel Volume Regulator Control Circuit Range/Performance Thoughts on if my AOS kicked the bucket while I was driving or if this is something more serious? Completely stressed out right now and hoping I'm not suddenly the proud owner of a roller.

It could still very well be the AOS there has been cases when they have completely failed with symptoms of a blown motor. The ingestion of oil and coolant can cause misfire codes.

Just wait till everything cools down first. Check the oil and coolant again and see if you have intermix. What yr is your 996?

2002 C4S. Will check intermix in a couple hours after car is cool. Absolutely crushed at the moment.

2002 is not known for cracked heads so my guess is a bad AOS, if there's no intermix and nothing is dripping out from the engine bottom. Crossing my fingers for you.

Engine is cool. No intermix and nothing dripping out from the engine. My new AOS should be here tomorrow. Will replace Saturday, followed by an oil change. Heart is still racing, but a glass of Oban helped calm the nerves somewhat.

Would be good if you can remove the throttle and the T plenum and check thr inside of the intake manifold. If it's the AOS, you should see lots of oil there. Also good to clean that up (can hold a lot) so you don't scare yourself when you see smoke again after the new AOS is installed.

If you haven't changed your coils, I would do that at the same time as part of your 120,000 miles service. Pelican parts have them at under $40 each. Slightly thicker with new type screws. Don't worry, the car will be fine.

Good luck with the fix, im sure you'll sort it all out.

Sounds pretty close to what happened to me when my AOS went. Really scary! And my engine hydrolocked too. But all was fine, so I think you may be happily surprised (if a $1,500+ bill makes you happy!).

Good choice of single malt Oban

UPDATE: AAA sent a truck that was too tall to get into my underground parking garage. Ended up pushing the car to the bottom of the driveway ramp, tow truck backed halfway down and winched my car 1/2 way up the ramp using front tow hook. Truck drove to top of the ramp and winched the car all the way up. Loaded on flatbed and taken down the street to the shop. Shop called and told me next steps. Step 1: AOS likely dead (replace it). Fix a coolant leak and replace some broken vacuum clamps. Run engine to burn off oil. Step 2: Replace spark plugs. Maybe replace catalytic converters and O2 sensors (depending on how much oil was ingested into the system). Step one isn't too expensive, but step two is not cheap. If I need new cats, I'll go aftermarket 200 cell. Very annoyed that I just replaced spark plugs a few weekends ago. All needs to get done as I have emissions due in a couple of weeks. Thanks all for the support.

If your car loses the misfires after the AOS replacement and no error code from the cats/OS, you can skip two completely.

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That's the hope!

Well, parts were delayed coming from Porsche and arrived late Friday so shop didn't do any work last week. Shop worked on the car today and apparently the diaphram housing on the new AOS is thicker than the old one, so additional delay in fitting new AOS. Tech finally started the car up at 400p and car is burning off a significant amount of oil. Shop stated it could take over an hour to burn off all the oil. May have to continue to run the engine in the morning if they can't finish tonight. Sitting here anxiously and hoping cats aren't toast, though I feel they are. Messaged with Fabspeed today and there's a 5 week build time. My emissions test is due by end of month so looks like my options are more limited than I'd like them to be.

why not just spend less? http://www.design911.co.uk/fu/prod15...Porsche-996_2/

Request the extension or whatever you have in Chicago for smog. EMISSIONS TEST FAILURES If your vehicle fails the emissions test, you must have the vehicle repaired, after which it must pass the after repairs emissions test. A Recognized Repair Technician should repair the vehicle. If your vehicle is unable to meet the emissions standard following the necessary repair work, you may be able to obtain a waiver issued by VSD prior to registration. You may apply for a waiver if the following apply: Your vehicle has failed the initial test and a subsequent retest. Your vehicle has received all repairs for which it is eligible under emission performance warranty. All emissions control equipment is intact and operational visually. You have spent at least $450 in emission related repairs. This amount is exclusive of repairs related to tampering. A recognized repair technician performed the repairs. All evidence of repair slips is presented at the facility. Contact the VSD's Test Stations to request a waiver or call [phone removed] or [phone removed] for more information.

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what's the consensus on the Design Tek vs Fabspeed? Looked like a couple of years ago a lot of people said Fabspeed had fit issues and I don't see those posts anymore. Hard to find much about the Design Tek on the forum.

Bam

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thanks very much for the suggestion!

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My 2002 Boxster experienced 3 AOS failures which at the end had the engine smoking like crazy and barely running. Two of these and maybe all 3 were with the original factory converters present. After the AOS was replaced and after some engine run time -- after the 1st one the SM told me it can take "50 miles" -- to burn away all the oil the engine and converters were just fine. If the converters were OK before the AOS failed it is very very likely they'll be ok afterwards. I'd give the car a heck of a road test to work any residual oil out of the engine and get the converters up to operating temperature and keep them there for some time. You can help the engine with Techron. I use a bottle that treats 20 gallons but dump the entire bottle into the 16+ gallon fuel tank and fill the tank full until the nozzle shuts off. Then drive the car normally. The general rule is if you notice any irmprovement from the engine to when the fuel tank level is down to say 1/4 a tank or a bit lower add a 2nd bottle of Techron and refill the fuel tanka and drive the car. After the 2nd tank with Techron is way way down it is best to change the oil/filter.

In theory you can 'help' oil contaminated cats by soaking them in warm detergent water. Shake, rinse,repeat. Youtube.Be cautious. If you didn't clean oil that was pooling in various parts of the Intake system(Because of the failed AOS) it will be a waste of effort.It will also be confusing(at best) because despite fitting a good new AOS ,the car will still smoke from all the residual oil in the Intake. Lots of tedious cleaning required to prevent this.

Thanks Macster and Schnell, great tips. Shop actually changed the oil as level was low following the smokeshow from last week. Got the car back today and the guys at the shop did a great job - ran the car for an hour this morning and by the time I picked it up, engine was smoke free. Too early to declare victory as I'll drive 100 miles or so to ensure no CEL comes on before taking it to emissions. Need to change spark plugs for 2nd time in 1 month, but car is driveable, acceleration feels smooth, and there's a big smile on my face. If emissions fails, looks like I can contest the ruling as I had more than $450 in emission related repairs...though I live in Illinois and would expect any contest to be a bureaucratic nightmare and cost me at least my firstborn and some kind of late fee.

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Why change plugs? If they were fine before the AOS failure and if the engine fires and runs with no untoward behavior they're fine. They might be a bit oily but this will burn off in no time. I mean the plugs get hot first in the combustion chamber since the plug tip is exposed to the combustion gases and it won't take but a handful of combustion cycles before the plugs are free of any oily residue. When the 1st AOS failed I was ready to change everything: Plugs, coils, MAF, air cleaner, have the intake removed and cleaned out, have the converters removed and flushed with solvent. SM said no need the residual oil from the AOS failure would work out of the engine/exhaust though it could take some time, the "50 miles" I mentioned in a previous post. When the replacement AOS failed -- the 2nd failure - and then that failed -- the 3rd AOS failure -- in both cases I just had the AOS replaced and resumed using the car. Had there been any issue I would of course dealt with it but there was none. All I did was just give the car a road test near the dealer just in case the engine acted up. I do this after an oil change, new tires, any work done just be sure there is nothing amiss. In the case of the AOS repair after some driving time and around town driving best as with this type of driving generally the engine gets hotter -- leave the A/C off -- and the intake and AOS and other hoses that connect the AOS to the intake run hotter which helps thin out any oil and move it along -- the engine was fine. After the 2nd AOS failure after a shake down drive around the dealer's area I drove the car approx. 90 miles to my parent's house and then after a few days driving the car back and forth between my hotel and their house to visit with them I drove the car 2K miles to home. After the 3rd AOS failure I didn't drive the car 2K miles but I just resumed using the car as I had been using it before and there were no issues. I mean of course it is your car and you do as you want but the plugs and what have you are almost certainly just fine.

I totally agree with what Macster says, except the part about "it is your car and you do as you want." This isn't subject to any democratic processes. Leave the plugs alone.

Plugs not being touched - will address if performance changes. Thanks for taking the time to share opinions.