02 jeep wrangler shows p0305, p0306. I know this means cylinder miss fire, but what would cause this.

Here's a link on your code.P0305 is cylinder 5 and P0306 is cylinder 6. https://www.obd-codes.com/p0300

P0346: Camshaft Position Sensor Intake Circuit Range/Performance Bank 2 http://www.autocodes.com/p0346_audi.html

P0391:Camshaft Position Sensor 'B' Circuit Range/Performance Bank 2
http://www.autocodes.com/p0391_audi.html

P0304: Cylinder 4 Misfire Detected http://www.autocodes.com/p0304_audi.html

P0306: Cylinder 6 Misfire Detected http://www.autocodes.com/p0306_audi.html

P0305: Cylinder 5 Misfire Detected http://www.autocodes.com/p0305_audi.html

P0300: Random Cylinder Misfire Detected http://www.autocodes.com/p0300_audi.html

Here's a link about your code P0306. P0306 OBD II Trouble Code

Not necessarily, you will just have to unplug it. The fan relay switch isn't that expensive so you should if you can. The multiple misfires usually means that you need a tune-up with plugs,coils and some sensors when required.

There are few possibilities that can cause engine misfire issues. It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

its faulty coil.

Get the compression test done on each coil.these will let you know if its faulty coil or not.

=========

It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

The page LINK here is the best i have read on misfire diagnosis, it is protected so I can't copy it but you can go to the link.

P0305 - Cylinder 5 Misfire Detected
P0306 - Cylinder 6 Misfire Detected

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, The Powertrain Control Module (PCM) or Electronic Control Module (ECM) can determine that a misfire is occurring.

When is the code detected?
- Engine Cylinder #5 and #6 is Misfiring.

Symptoms:
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/loss of power
- Hard start
- Engine hesitation

Possible Causes:
- Improper spark plug at cylinder #5 and #6
- Insufficient compression at cylinder #5 and #6
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #5 and #6
- Fuel injector #5 and #6 may be faulty
- Intake air leak at cyli

Possible Solution:
- Perform Injector Service
- Replaced Spark Plug #5 and #6
- Replaced Injector #5 and #6
- Replaced Ignition Coil #5 and #6

Hope helps.

HI. The codes and their respective definitions are below.


P0300 - Random/Multiple Cylinder Misfire Detected
P0305 - Cylinder #5 Misfire Detected
P0351 - Ignition Coil A Primary/Secondary Circuit Malfunction
P0306 - Cylinder #6 Misfire Detected

For the 1998 Lexus GS 300 3.0 liter DOHC

Firing Order:
1-5-3-6-2-4

Cylinders:
(back)
...6
...5
...4
...3
...2
...1
(front)