I've got a number of trouble codes that point to a vacuum leak. I pulled off the engine covers and started poking around. I found that the crankcase breather hose between the cylinder heads has taken on the consistency and structural integrity of an overcooked spaghetti noodle.
I've discovered that Auto-Zone Heater Hose Part number 80416 "Dayco/Hose (Lower)" can be trimmed to an acceptable fit for replacement. It costs $10.99. I was originally concerned that the hose would collapse under vacuum, but in initial testing that has not been an issue. If it becomes a problem I will insert a length of 1/2" ID Convoluted Tubing (the stuff you use to organize wires into neat bundles) in the long section.
To install it:
- Remove the engine covers over the valve covers with 4 5mm cap head allen screws.
- Remove the 4 cap head allen screws for the center engine cover.
- Remove the two worm clamps, one near the oil filler cap, one on the passenger cylinder head.
- Pull the hose off. If it's rotted like mine it will come off in pieces.
- Trim ~2 inches off the short end of the AutoZone part.
- Test fit it on the oil filler cap end.
- Test and Trim the appropriate length from the passenger cylinder head end of the hose.
- Install the hose with new worm clamps Note: These are a -tight- fit. I could not use the OE clamps and had to use flat clamps from AutoZone. I had to push them into place with a screwdriver.
- Tighten up the hose clamps.
- Replace the engine covers.
Here is a terrible picture of the completed installation.
I hope this helps someone else.