1999 Nissan Pathfinder 3.3 4wd P0300

Question

Missfire at cylinders 1, 2, 4, and 6 at high idle. Steady service light while driving and sometimes flashes at a light.

I've replaced the distributor, plugs, wires, fuel pressure regulator, fuel pressure sensor, checked the timing @15°, and fixed a crack in the intake duct, vacuum hose leak, cleaned all electrical connectors around motor, checked fueses, swap relays, ground wires. Fuel injectors 1, 2, 3, and 5 are clicking and injector 1 resistance was 12+

Checking the vacuum hose, injectors resistance, and connector under the intake plenum not done do to having to remove the plenum. But I've sprayed starting fluid under plenum and the RPM stayed the same.

Other than selling it what can I do next and what is left that may cause the code.

Answer 1

The fuel injector resist may be within specifications, but it's very common for the fuel injectors to get clogged. There was factory service bulletin for the problem and the factory recommends to use fuel cleaner to fix the problem.