idle irregular after puting in new air/oil separator,
 

Replaced the A/O , and cleaned the m.a.f. -bad surging idle. , after a 15 mile drive, it was better, not perfect.
Will it?

- prior to this i had a check engine light come on, code was p1275, for a o2 sensor on 1-3 bank. No change with new sensor, so we replaced the o.a. -it is not throwing any codes now.

Will the dme re-learn with a few more drives? Or is it possible i have
a vac leak? All the o.a. sep connections look good.
- oh, and when it was idling bad when i disconnected the m.a.f. sensor the idle smoothed out a bit.

Bad M.A.F. too?

--2000 boxster S 70k miles

Wow, looks but no comments on this issue? i am suprised. So looking over on the bird board, it seems that bad or dirty MAF sensor can do this, and after cleaning or replacement it takes a little while to "relearn" sometimes, - so when the weather clears off i will go ahead and drive again see it this clears out, if not i will be ordering a new MAF - any recommendations on sourcing these? I see them anywhere from @ $100 on amazon , $250+ pelican, and Porsche crazy dollars!

advice and input appreciated,

Thanks

Start with the easy, cheap stuff, if you have a Durametric, you can easily diagnose a vavuum leak, not where it is, but that you have one, then go over the connections you loosened again, and the ones near it.

If you disconnected the MAF and its better, then it could very well be the MAF, but I would do some more research on MAF diagnostics before getting a new one, just to be sure.

The A/O separator needs to be air tight. You may be sucking air in around the lower tubes. Get a smoke puffer and check for leaks.

i was afraid that somehow vacuum leaks might be the issue, usually a surging
like that i know with the older cars like my 914 with injection is either vac leak or a lean running condition. 99% of the time its one of those two. a little more complicated with the boxter, but really overall its very similar.

i will double check the clamps on the lower connectons of the O/A.

Thanks

good to go now!
 

FYI following a couple drives, it seems the DME "relearns" and balanced out. Idle is now even and steady with no surging or variations! also gas milage last tank was 25.5 combined driving to work, about 40-50 mph with a few stops, 20 miles driving each way - about what it had been before it went south. No codes showing at this time, but iwll hook up to the computer to make sure codes have been cleared. I understand that even if the CEL is not there, the DME may still not have cleared the codes and may not be running 100% as it should.

How does one find a vacuum leak with a durametric? I may have a leak and would be willing to buy the cable if I was sure it could tell me there is an actual leak