Misfire cyl 4, 5, and 6!

[drakeguy22]

So im throwing all these codes at the same time.... P0304,5, 6... P0171, P0174, P1151, and P1152.... This all happened a little while ago.... i went to get an inspection in NY(yay) anywho failed cause of the o2 sensors... i bought them... check engine light never came back on so they passed it... anyways it started studdering bad... long story short, its a Sohc, 100,000 miles. pretty new plugs, JBA 9mm wires, stock intake, exhaust has got a pretty good leak in the muffler... im thinking that the cat is clogged... the exhaust pops from time to time as well... im about to pull the cats off ang gut them so lemme know what ya guys think

 

[drakeguy22]

come on no one???

 

[drbenz]

As much as the intake gaskets like to leak I would start by shooting some throttle body cleaner on the intake while its running and see if it makes a difference in how it runs.

 

[MonsterTruck460]

Bad coil?

 

[drakeguy22]

so i replaced the o2 sensors... same problem... it runs ok when i first start out... as soon as i get going about 3rd gear... it starts misfiring and i lose a lot of power... but if i floor it i got all of the power back

 

[JG88]

I had the same issue with my 97 around 100k. It misfired on every cylinder when driving in the city, but once I hit the highway it was all good. Turned out I had a chewed up wire that was shorting out to the chassis. Check your wiring and your coil.

 

[2000StreetRod]

Engine misfire procedure

Engine misfire procedure

 

[hookem_78]

I'm having misfire problems too. 2000 ford explorer 6cyl. sohc. cyl 4,5,6 misfire sometimes, but not allways. plugs and wires look good. fuel filter is good, and there is no sulfur smell or black smoke coming out of exhaulst. during misfire engine shutters, struggles with power, and shifting. when i punch it, it does eventually take off. what do you guys think it is???

 

[2000StreetRod]

Cylinders 4, 5 & 6 involve all three sections of the coil pack but only bank 2 of the engine. Ford uses a waste spark ignition system (two plugs fire at the same time) so if the coil pack were bad there should be misfires on all cylinders. You might check to see if there is something metal against the ignition wires shorting out the driver side.

The problem could be fuel related. There might be something restricting fuel flow to the injectors on the driver side. Or the injector wiring harness on that side could be unreliable.

Another possibility is poor compression. You could have a blown head gasket or a slipped timing chain on that bank.

Do you have any other codes besides the misfire codes?

 

[hookem_78]

the first time i checked the codes, it was just the cyl misfire codes. I reset the computer by disconnecting the battery, then a few days later when it was struggling again, check engine light flashed few times and then stayed on. when i checked at autozone this time, it had the same cyl misfire codes, and one other code. not sure what the number was. dont have the printout in front of me, but i believe it was a lean bank 2 code. i just looked at the ignition coil a little closer, and noticed some metal showing on the black wire that comes from the plug going to the coil pack. would a wire shorting out cause only bank 2 to misfire??? thanks for the help my man.