muttsjet

1) Have gone thru threads but didn't find a similar scenario:

- check engine light
-- smoke on startup that does not smell light gas but does smell like something is burning
-- RPM randomly jumps up a couple hundred RPM then stabilizes out
-- car drives just fine with no smoke (ie, only on startup)
- resetting light makes light go out but it comes on after about 80 miles

Got OBDII today from Autozone but no code since I had recently reset by disconnecting battery. Will check again once check engine light reappears.

2) assuming you reset check engine light and had no codes, should car pass emission inspection if taken in before check engine reappears

3) same question as 2) but headers (with 4 O2 bungs) installed inplace of pre-cat

Dave H.

no, you have to reset the readiness bits after you clear the fault. if you go for the test and the light is off but the readiness isn't clear, you can still fail. (how many bits depends on the state you're in).

you won't know anything until you get the fault code...

Turboflyer

I think the fault code has to be reset. Just disconnecting the battery will not do it. Try running your scanner again and I think you will find the fault code. The light may not be lit but the fault code is stored. Most likely the higher idle is just the cold start and recirculation pump at work. Sounds like your air oil separator is starting to go and causing a check engine light Will be interesting to get the actual cause.

Macster

driving of the, even running of the engine as possible. Ideally, none.

Answer to (2) is probably not. When check engine light reset/cleared DTCs are cleared along with readiness monitor test results and long term fuel trims.

Engine needs to be driven some for the readiness monitor test results to be flagged complete. Chances are check engine light will come again before this happens. Some states allow up to 2 readiness monitors not complete but after clearing them all will be set to not complete and driving is the only way to get them to complete.

(3) depends upon the state where you live and its emissions/smog check requirements and how careful/thorough techs are when testing cars. Since there is no little risk to these businesses (lose their business/emissions test license) if they screw up and because of concerns about uncover investigations you'll probably run up against a pretty good/thorough test.

Besides, engine runs best -- and cleanest (that's everyone's air you're dirtying up) -- if O2 sensors in place.

Sincerely,

Macster.

muttsjet

Turned out to be air oil seperator. About $100 w/shipping. Instructions on how to DIY on 986forum. 2-3 hour fix. Only tools required 10mm socket wrench and pliers.

Turboflyer

Glad you found it and decided to fix it yourself. Try and make sure you get new inventory and not the same old style AOS. According to one source Porsche went through about 6 changes. I think there was a post some where showing the obvious outside difference. I took my old one apart and sure enough the large diaphragm had ruptured. Not much else in there but chambers. I don't usually care what people think, but it sure was embarrassing to fire your baby up at work and look like, well you know. Good luck on the install.