This was wild. For well over a month now I've been chasing down a lean at idle problem. At idle the o2 mv would dance around 20 (VERY lean). I replaced the fuel pump, cleaned the injectors a second time, replaced filter, blew out the lines, all with no luck. I spent countless hours pulling everything back off and retightening things, replacing lines, everything I could think of and again no luck. So today I was doing the usual hunt for a vacuum leak when I got frustrated and yanked my oil breather and put my palm over the hole. INSTANTLY the mv went from about 20 to 1100. hooolllyy craaap. Ran and grabbed a new oil cap, slapped it on there, and now it runs perfect! Who knew?? The odd thing is I've had it on there for a long while, and the idle issue only seemingly just came up more recently...oh well, seems to work for now hopefully it lasts

Me too, Doc! When I put my breather on for purely cosmetic reasons, I observed the same. My idle changed (after re-learning, it was for the better), felt more power, and the car runs more efficiently.

Huh? :? A breather cap or a new stock filler cap?
I've been running my California Custom'* breather cap on my B-ville'* for the past 16 months. Didn't think it was much of a benefit beyond eye-candy.

Yeah i'm talking oil breather cap....obviously made mine run really lean at idle

Is that the thing that is like a small air filter where the stock oil fill cap is?

What are the purpose of those things?


-justin

I dont know but whenever I think about buying one they arent screw on types, just filters with the tiny hose at the end of it which wouldnt fit.

does that mean you've got a lot of blowby?

I'm pretty sure that there to relieve crank case pressure when you disable your pvc.

As long as you have a functioning PCV why would one need a breather? Not doubting it helped you, just curious.

My pcv is new