Check Engine Light

Orions 04GT · Aug 29, 2009

I have a 04 GT 4.6 SOHC. I'm getting a bunch of codes P0300 P0316 P0301 P0304 P0306. So it is telling me the I'm getting a random misfire, misfire below 1000 rpm at start up and cylinder misfires. I did a search on this from the forum and found some info. I have changed the plugs (Motorcraft SP-493) and oil at the same time. I'm still getting codes. I changed the fuel filter. I've swapped coils with out changing what cylinder is misfiring. Is there something I'm missing to get this problem to go away. The car has only 44,000 miles.
The only MODs are a cold air intake, Free flow mufflers and under drive pulleys.

Any and all input is welcome and thanks in advance for the help.

soupnutz · Aug 30, 2009

Just sitting there idleing can you tell it's missfiring? Vibrations and rough sounding exhaust? A lot of time you can pull injector harnesses one at a time, if it gets worse that cyliner is good, if it styas the same thats the cylinder that missfiring.

Orions 04GT · Sep 5, 2009

Orions 04GT · Oct 6, 2009

Found out what was causing all my codes. I installed underdrive pulleys awhile ago from summit racing. Decide to start removing some of the mod's I did when I removed the balancer I noticed that the keyway in the underdrive pulley was all messed up. I removed the underdrive set up and no more codes. I did have too change the oil and clean the plugs. So it was a timing issue as the balancer must have ben rotating back and forth damaging the keyway. So if anyone else is having this type of problem and you installed underdrive pulleys check the keyway in the balancer pulley for damage.

trinity_gt · Oct 6, 2009

UDPs would always be the first place I'd look if misfire codes show up on a car so-equipped. Typically, the problem is that the pulley bolt isn't tight enough and the timing wheel -- between the back of the pulley and the front of the timing sprocket -- isn't tightly sandwiched in place, leading to sloppy timing signals being picked up by the CPS. Usually, misfire codes caused by UDPs can be eradicated simply be replacing (because it's TTY) the crank bolt and re-tightening it to factory specs.

Having said that, I wouldn't do the UDP mod anyway because the gains are minimum and there is the potential for additional risk to the powdered-metal oil pump gears due to insufficient crank-snout damping caused by incorrect dynamics of the replacement damper.

Stark77 · Oct 6, 2009

Steeda UPD's, SFI approved and they actually make power.

trinity_gt · Oct 6, 2009

I'd rather have the correct mass and elastomer durometer as designed by the modular engine engineers, verified and validated by untold hours in Ford's engine dyno cells, than an SFI rating and 4HP.

evolucion311 · Aug 18, 2011

Orions 04GT said:
Found out what was causing all my codes. I installed underdrive pulleys awhile ago from summit racing. Decide to start removing some of the mod's I did when I removed the balancer I noticed that the keyway in the underdrive pulley was all messed up. I removed the underdrive set up and no more codes. I did have too change the oil and clean the plugs. So it was a timing issue as the balancer must have ben rotating back and forth damaging the keyway. So if anyone else is having this type of problem and you installed underdrive pulleys check the keyway in the balancer pulley for damage.

Bummer, dude. I cheaper out and tried a set of Summit-brand blue pulleys. Big mistake. The supplied crank bolt was too long and a damn near stripped the threads in my crank shaft. I took em back and got a set of Steeda UD pulleys. One year and 20,000 miles later they're still good to go.

Deleted member 38176 · Aug 18, 2011

evolucion311 said:
Bummer, dude. I cheaper out and tried a set of Summit-brand blue pulleys. Big mistake. The supplied crank bolt was too long and a damn near stripped the threads in my crank shaft. I took em back and got a set of Steeda UD pulleys. One year and 20,000 miles later they're still good to go.

+1

When it comes to UDP's, it's STEEDA or bust

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