Chrysler Repair: P0300 chrysler sebring 1998, oil filler cap, sebring conv

Question
I have 98 chrysler sebring conv. random misfire p0300. I replace distributor cap, rotor, plugs, wire set, new distributor, fuel pump, fuel filter, EGR valve, and still P0300. Compression OK, but manifold vaccuum only 17 hg. Please help

Answer
Hi Vu,
Is the reading on vacuum gauge steady, or varying? 17" of vacuum is in the correct range of 13-22" but describe any variation if noticeable.  Have you tried spraying very short bursts of starter fluid around the perimeter of the intake manifold while the engine is idling to listen for a change in the idle speed which would be a sign of an intake manifold leak? Be careful to just use a tiny burst due to flammability.
Have you checked all the hoses that are attached to intake manifold to look for a cracked hose or loose fitting?
The remaining  possibilities are ground connections of the powertrain controller may be flakey (check the ground at the left strut tower and at the bolt on the rear of the cylinder head near the oil filler cap), injectors may be clogging up, or the honeycomb in the catalytic converter could be loose and off-axis (that partial clogging can be detected by an exhaust shop).
I hope one of these may help. I assume that you erased the code by disconnecting the battery briefly so it is truly a 'fresh' code.
Roland
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