Hi,
A P0303 is a very specific code. Since we have that code, we need to focus on cylinder 3. Since this happened after the clutch replacement, I doubt it has anything to do with the engine internals. I suspect that we have a wiring issue for the cylinder 3 injector or coil.
First, have you double-checked to make sure there are no pinched wires that resulted from the previous work? If not, take your time and check.
Next, although you feel the misfire below 2000 RPMs, it is likely happening above that as well but less noticeable. What I need you to do is this. First, remove the cylinder three spark plug and inspect it. Let me know if it is wet with fuel, dry, any discoloration, or anything you see that seems odd.
If the spark plug is dry, the next thing I need you to check is power the cylinder 3 fuel injector.
If you look at pic 1 below, it shows the fuel injector wiring. Note that all injectors have a red wire. That is the power supply. Disconnect the injector. Check for power at the red wire with the key in the run position. Confirm that for me. If you are using a test light, put the alligator clip end on the battery negative (or a known good ground) and probe the red wire with the light. It should turn on. If it does, disconnect the alligator clip and attach it to the positive side of the battery. Then, probe the other wire at the connector. In this case, it will be a black wire with a red tracer. When you probe that wire, have a helper crank the engine. The test light should strobe on and off. Does that happen?
Before I get into the coil wiring and overwhelm you, try this and let me know what you find. If this is working correctly, we will then check the coil.
Let me know what you find.
Joe
See pic below.
Mar 2, 2024 at 3:13 PM
