Rick Hesel

After being plagued by misfire CEL trouble codes for the past six months and several unsuccessful trips to dealers to find and fix the source of the problem, I think I've found the problem myself. I've been through a few driving cycles with no CELs, which before the fix were triggering every time I drove the car.

The problem? Evidence points to a leak in the vacuum hose that connects from the valve cover to the intake manifold and, I think, has a role in regulating fuel pressure. The leak occured, I think, because the stainless braided hose I installed in place of the stock hose was too stiff, and engine vibrations were probably pushing the plastic conncector to the valve cover (which sits in a rubber grommet) out of alignment enough to create an intermittent vacuum leak. I replaced the braided hose with a much more flexible silicone hose this morning, and the CELs have disappeared.

That at least is my theory. I'm going to go through as many driving cycles as I can over the weekend to be sure the problem does not reoccur.

Since these misfire CEL codes have been popping up for many other owners, I'll report back results one way or the other. My fingers are crossed.

wortham

here's another set of crossed fingers and toes for ya, rick.

hondaS2001

were the cel's blinking or solid?

Slows2k

What hose are you taling about? There are 2 hoses off the valve cover. 1 is the PCV valve, the other is the breather hose that goes to the intake tube in front of the throttle body. Neither one controls fuel pressure. A vacuum leak at the PCV hose would cause a lean condition on cyls' 2, 3. And could cause misfire DTC's P0302-P0303.

The hose for the fuel pressure regulator goes straight from the regulator to manifold vacuum.