Code p405, im thinking its the wiring to fuel injector #5 but im not sure which cylinder #5 is...lol I have a 2002 Jeep wrangler sport straight 6.

Is this a 4.0 liter or a 2.5 liter wrangler? Sometimes the crankshaft sensor causes these things to make these codes come up. Crankshaft position sensors are very common of going bad on Jeep vehicles.

Sounds like an intermittent miss. Possible worn plug, bad wire, or an injector that is shorting out. Check to see if any codes are set. This will help you narrow the problem to a certain cylinder.

Are there any driveability issues, can you feel the misfire? Just about anything can cause a misfire, did you visually check for spark? check your fuel pressure and fuel injector. Also, check cylinder compression. Sometimes the code isn't valid because of faulty sensor, somewhere.

If it was fuel related it would have sputtered as it ran out of gas. I think it is lack of spark caused by a failing crankshaft or camshaft position sensor.

Check the plugs, wires and coil pack for these two cylinders. Most lilkely it is the coil pack, they work for 2 cyclinders at a time. cylinder motors use 3 and 8 cyl moters use 4 of these. If your und=sure where the coil pack is, follow it backwards from the spark plugs.

a miss fire can be caused by a bad fuel injector or wiring to the fuel injector. Do a self test on the computer. turn key off-on, off-on, off-on. The codes with flash out in pairs on the check engine light, 5-5 being the end of the test. It may identify the problem cylinder. IF you do find a stuck injector you can try the redneck fix. Put a long socket extension on the injector and tap lightly with a hammer while the engine is running. TAP LIGHTLY!!! ITS ONLY PLASTIC!!!!! This may free up the injector. make sure spark is reaching the plug.

check security of the wiring for fuel injector for cylinder #2. Check resistance of this injector and compare the reading to another injector. replace if needed

There may be an issue with your fuel pump relay or its wiring. however service injector first to see if trouble code does not return

cylinder number 2 has a misfire

Hi JHWalker
I would try doing the fuel pump filter or fuel pump itself if they are one unit.

Hope this help you.

Matt

Check your fuel injector for that cylinder. Maybe you have too much build up in that injector and its not spraying enought fuel in the cylinder.