I have numerous OBD codes that start with P0300, P0302,P0304,P0306 all misfire on 2005 Kia Sedona

codes. I have changed the coils and plugs and the codes are still there. What are chances that it could be the catalytic converter being plugged or bad fuel filter? I would think that if the problem lies within that all codes for cylinder would be on. Just seams to be that 2 ,4 and 6 cylinders affected. Please Help!

by in Milwaukee, WI on April 12, 2014
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3 answers 6 comments
ANSWER by , April 12, 2014
Think outside the box, do you have any equipment for further testing, and what else can cause a misfire indication on one side of the engine.
COMMENT by , April 18, 2014
Yes, what else would I need? I replaced the coils and it did not make any difference, there are just the 3 coils in the front by the engine that send spark to all the plugs correct? I dropped both sides of the convertors and it ran a little better but still no power and codes came back. Still at a loss. Could it be bad injectors? or just one bad one?
COMMENT by , April 18, 2014
It could anything that causes combustion or is not allowing proper combustion for the cylinders to function properly.
COMMENT by , April 19, 2014
what else I can I check for combustion? Is this a problem with this vehicle? I have not read anything else on this site for this particular problem.
COMMENT by , April 19, 2014
What has to be right for the explosion process to occur. Good spark right amount of fuel and good compression at specific timing point. That's when combustion happens to make the engine run.
COMMENT by , April 21, 2014
I have taken cover off to check timing belt. I looks like the belt is very worn and tension-er is not working correctly. Could this be the cause of misfiring to just one head? If the timing is off on one cam or the belt is slipping would this be a misfire codes? By re-timing the engine and putting new belt and tension-er in make this all go away? Is putting new belt in and and tension-er very hard to do on this KIA?
ANSWER by , April 12, 2014
What did the old plugs tell you (all plugs give information) Do you still have the old coils?
COMMENT by , April 19, 2014
the plugs looked black and carboned, on the front side of the engine. Which I think are the 2,4 and 6 cylinders. That is why we replaced the coils to see if it was a bad coil not igniting the plugs. Is this a correct procedure? I have not checked combustion on this head because I do not have a pressure gauge to do this.
ANSWER by , March 09, 2015
did you fix this issue???