I would check the resistance of the number 4 fuel injector with it unplugged, and multimeter set on Ohms, The Test light check is very easy to do as well, but the reason the resistance check on the injector is if it shorted out internally, the current flow to the Injector driver inside the engine computer (ECM) could have burned out the driver. It's the main cause of drivers in ECMs being burned out, same goes with ignition coils that short out, too much current flow and the driver gets cooked inside the ECM and the driver will never be able to activate the Injector again. With a resistance of 11 to 18 ohm, with a 12volt circuit, that's less than 1amp of current driving that Injector. I'd would not like to see you replace the injector and still have a failed number 4 fuel injector circuit.
The test sounds more difficult than it is, and it actually takes about 5 minutes.
Since the ECM pulses the negative (ground) wire of the fuel injector to control it, all you need to do is have a test light hooked to battery positive and touch the pin on the fuel injector plug and the test light will have a dim flash to it. You're just using the test light as a substitute instead of the injector. The guide below is very simple to follow.
This is a circuit code, not a cylinder number 4 misfire code, that's why I'd recommend the testing. The ECM is detecting something electrical wrong with the circuit.
If you're really too uncomfortable doing the testing I understand. But don't replace all 6 injectors, just do the number 4 first. After replacing the injector, you will need to erase the code because the ECM may have shut down that circuit due to the fault.
And if in the worst-case scenario, the code comes back after the injector replacement, then the ECM control circuit needs to be checked, so keep the bad injector just in case.
One last thing, if the injectors from Ford are not too expensive, you should get a Ford injector. Aftermarket injectors from AutoZone, advanced auto, etc., places, can have a different flow rate than the OEM (stock) injectors. They almost always do.
Wednesday, September 7th, 2022 AT 7:24 PM