2004 Ford Expedition runs rough cel flashes when accelerating and has no power

What are the codes?

I was told code says cylinders misfiring

Flashing CEL are most of the time misfires. Misfires can happen for a host of reasons but start with spark plugs and coil testing. A definite code would get you closer to what cylinder is affected. EXAMPLE: P0305 is a misfire on cylinder 5. You can then do some tests on that coil and plug to see if this is the root cause. A simple test is to label your coils and then swap 2 coils to see if the misfire moves proving a defective coil.

Could have the elusive P0300 code. Random cylinder misfire. Then you have to get into checking compression, fuel delivery and vacuum leaks and worn gaskets.

plugs and coils were replaced as well as fuel pump

one more thing, it seems to run better when it's cold but gets worse as it warms up

There is a such thing as bad new parts. Especially if you did not elect to put on OEM parts. Hopefully you used Motorcraft coils

At this point get an exact code to narrow cylinder or cylinders.

would an injector cleaner help?

It could. Injector could just be wore out? Injector pulse issue. Wiring to the injector? Again you need to narrow issue down by retrieving the codes. Auto parts store will pull codes free.

Bad coils can test and run good when cold then test and run bad when hot. I had this on a Corolla with 2 bad coils. Tested close to good coils when cold but when hot were bad. Switched both to known good cylinders and misfires moved.

cylinders 1,2 and 4 are misfiring

I can't see 3 out of 8 coils being bad

I can if they are original coils. But you say they are new. How about a leaking intake gasket? They are even cylinders and I believe they are on one side on that Ford

I'm having the same issue just replace the coil and plug on the number 4 and it's running a little better but still staying in low rpms and no acceleration