Service Engine Soon light flashing

On the way home today my 2001 mustang 3.8 L started misfiring. I noticed that the service engine soon light started flashiing. I pulled into the auto zone to check for codes. No codes. I figured that maybe i got a tank of bad gas. I poured a can of seafoam in the tank and drove until the tank was empty. It continued to misfire under a load. I put a fresh tank of gas in the car and its still missing out. I changed out the fuel filter but it didnt help. The car is still missing. I was think of changing out the spark plugs they have about 55k on them. If that doesnt work i was thinking of getting the injectors cleaned. Any thoughts?

When it flashes it means it's misfiring! Has anyone done a tuneup ever to this car?

I have changed spark plugs, and done all normal maintenance oil changes, fuel filter, air filte. I just changed the plugs and the miss isnt as noticable. Under a load i can feel a slight miss. I was thinking of taking it in to a Valvoline center and letting them clean the fuel injectors.

The money would be better spent on diagnosis then services that probably won't fix it!

Is it a coil on plug system or does it still use a coil pack with wires to each cylinder?

It's a coil pack with wires running to each cyclinder

Have you tested them or done anything to eliminate bad ignition wires?

I pulled the plugs wires one at a time while the engine was running. I held then about 1/2 inch from the plug. There was a good fire on each plug.

Yeah but that test doesn't confirm that wire isn't bad it just confirms that there is spark out of that coil!

Do you know of a test that i can perform to check the wires? I appreciate your guidance on this.

Put a little bit of salt and some dish soap in a spray bottle and mist the wires with the water, if the wires are breaking down or what they call cross arcing you'll likely hear it and if you do it in a dark garage or driveway you can often see the sparks. If you have any replace the wires. If they don't cropss arc they can still be bad , you can test them for high resistance with a multi meter but it's not the most accurate test, it's okay for testing for an open circuit but when the wire is flowing voltage it can still break down and not show with a static OHms test. the rule of thumb is if in doubt replace them. The boots often get damaged removing them for a tune up and if they're original on the car then it's good preventative maintenance

Thanks..............I'll go ahead and pick up a new set.

I bought a set of new ignition wires and replaced the old ones. The miss is still there. I took the car and had the fuel injectors pressure cleaned. That did'nt take care of the problem either. I'm thinking maybe one of the fuel injectors is bad. Any thoughts?

Im thinking a scan tool hooked up telling you live data and misfire monitor would be nice to have. Of course the injector cleaning won't fix it I think I said save your money on that one and invest it in diagnostics instead. But sure price 6 new injectors if you want

When does it misfire? All the time or when you accelerate? At what rpm range? Try this remove the vacuum line from the egr valve, plugging the line and drive it and see if the misfire is gone. If it is I can tell you how to fix it.