View Full Version : po 301 code

01-22-13, 03:37 PM
OK need some help on this one... I have a 97 catera, got a check eng. Light ran it and it was pro 301, pulled the #1 plug boot and found that my valve cover is full of oil, and I mean full, over the spark plug full, I mean you can't see the plug.. It was leaking a little oil, nothing weird there, can anyone tell me what's going on??? I know its not draining back to the crank case, but why?? Any easy fix

01-22-13, 05:09 PM
check the breather box probably clogged up and change the valve cover gaskets. Also, plugs may need replacement.

01-22-13, 05:21 PM
OK, thanks for reply... Where's the breather box??? And that spark plug thing you mention. Oh yaaa

01-22-13, 06:12 PM
The breather box is located on the passenger side right behind the valve cover area. There are two hoses (one big and one small) that goes from the breather box to the upper intake black plastic piece (four hose hook up ends on one end). It goes across the upper intake to the throttle body. It could be clogged up too, remove the black plastic strip out slowly and there's a rubber O ring under the plastic piece. Remove that slowly without breaking it and also the two tiny O rings on the other end of the plastic that goes to the throttle body. Then spray some carb cleaner throught it and also check the breather box openings, use a paper clip or something similar to the tiny opening and clean the gunk out.

Once all cleaned out install the three rubber O rings back and work on the valve cover gaskets and plugs.


01-22-13, 06:30 PM
Thanks again.. This one had me baffled.