2001 Jeep Cherokee with 6 cylinder engine -- PO306 code cylinder

PO300 and P1399 are random cylinder misfire detected.
PO301 cylinder 1 misfire
PO302 cylinder 2 misfire
PO304 cylinder 4 misfire
PO306 cylinder 6 misfire
I would say that you have damage to the ignition wiring harness or you ECM is failing.

Possible Causes:

• * Air leak in the intake manifold, or in the EGR or PCM system
• * Base engine mechanical problem that affects only Cylinder 6
• * Fuel delivery component problem that affects only Cylinder 6 (i.e., a contaminated, dirty or sticking fuel injector)
• * Ignition system problem (coil, plug) that affects only Cylinder 6

Coils and wires most likely got wet .

Diagnostic Test Code (DTC) P0306 is defined by SAE J2012 (REV, DEC 2007) as "Cylinder 6 Misfire Detected".

To put it plain and simple, there is a problem with cylinder #6 in your engine that is causing it to misfire.

Misfires can be caused by several things. One of the things that must be understood is that a misfire is simply one or more cylinders that are not producing the power that they should. - especially when compared to other cylinders in the same engine.
The things that can cause this include, but are not limited to:
> Ignition system
> Fuel delivery system
> Fuel injection system
> Cylinder compression (which can be affected by many of the things below)
> blown head gasket
> Burned or bent valves
> Vacuum leaks
> Faulty wiring
> cracked piston or broken piston rings
> Restricted exhaust
> malfunctioning Powertrain/Engine Control Module (PCM or ECM)


To fix the code, you must first diagnose to determine which of these things is causing the misfire, then repair accordingly.

po206 is the is the inj. 6 not responding to control signal.
po306 is a misfire in the no.6 cylinder..
Check your ignition leads or the coils.
Ummm the spark plug.
It's a bit hard over the net but I hope this helps you

a blinking ck engine light means you have a catalyst damaging misfire. the misfire is also the cause of the shaking and probably low power condition. you need to have the vehicle scanned asap and try to figure out which cylinder or cylinders are misfiring by the code read by the scanner. if you have a po300 code it means you have a random cylinder misfire. if you have a po301 through a po306 then go to the cylinder 1-6 designated by the last # in the code to figure the cause from there. look for a burnt plug wire, remove the proper sparkplug and ck it. also remember to change the engine oil as there is unburned fuel getting into it every minute this condition exists that the engine is running. good luck to you.

Sara,

Follow the listed link...it will tell you everything about P0306 code.

Hope this helps


http://www.engine-light-help.com/P0306-check-engine-light.html

Cylinder 3 AND 4 are the hottest of the straight 6 engines, the misfire is most likely caused by coolant seeping into the cylinder and shorting the plug out. If this continues it will eventually burn/blow the head gasket out from between the 3 and 4 cylinders. You will need a compression test and a radiator pressure test to determine if you have coolant seeping into the cylinder. If you do you will need a valve job (Possibly a new or rebuilt head). Also flush the cooling system out while you are in there.

1.Plugs
2. Vacuum leak
3. Injector fault
4. High or low fuel pressure.
Thats the list of things to check.
This is a #3 cylinder misfire.
There is also TSB about #3 injector needing added heat protection. This could definitely be the cause. I start at plugs and go from there.
Hope this helps.
Thank you,
Lee

try changing your crank senor. Get part from the dealer... My jeep was misfiring and changed OEM part and jeep rides good.