i have a 2003 land rover discovery randomly started misfiring. started off at one cylinder (cylinder 4) so i replaced the coil wire and spark plug and it didn’t fix it then i drove it a little and checked codes again and now it’s 4 different cylinders misfiring. i replaced the crankshaft position sensor and it didn’t fix it. i had a thought it could be the camshaft position sensor but i’m not sure where it’s located and what goes into it. it’s not giving me any codes besides random misfire and then different cylinder misfiring codes. i would rather not replace the camshaft sensor if it’s not the problem i’m stuck and don’t know where to go from here.

 

which specific cylinders are the misfires on?

 

i’m getting a code for a (random misfire causing damage to cats) then i’m getting misfire codes for every cylinder. then last i get a emissions leak code but i had that before the misfires started so i doubt that it’s related

 

One more possibility, worn out camshaft.
I had that.

 

Did you replace the ignition coil? I had random misfires, and replaced the ignition coil, connectors, sparkplug wires, and sparkplugs and it solved the problem.

 

i was going to but i tested the wires with a spark tester and they all had spark so i assumed it was fine.

 

Maybe check fuel pressure. Easy to do. Could be bad gas.

Always nice to have new plugs and wires, especially if you don't know how old they are. Plugs will give clues about what is going on. Perhaps start with ignition components before moving to sensors, depending on maintenance history.

Scan real time OBD information, especially O2 voltages and fuel trims. That tells a lot about engine function.

 

Only getting random misfire codes? Open the hood with the engine running at night and see if you can see any spark jumping. If you do decide to change coils/wires, you might want to look at this: https://extinctmotorsports.com/the-e...g-perspective/