My car is missing. I have changed out spark plugs, changed fuel filter, fresh oil changed. What else could be?

likely bad spark plug wires.
My car is missing. I have changed out spark plugs, changed fuel filter, fresh oil changed. What else could be?
spark plug wires...
My car is missing. I have changed out spark plugs, changed fuel filter, fresh oil changed. What else could be?
Somebody might have high Jacked it and took it for a spin then left it there then stole another.
is it fuel injected as it could be one of the injectors not working to find out which cylinder is missfiring you will need to disconect one of the H/T leads (spark plug wires) one at a time as it is running, if the engine dies or stalls then you will know that one is firing so go to the next one until it makes no different to the running (Missfiring) then you will have established it is that one that is missfiring hope this helps it could be complicated to suggest this to a novice if you do decide to pull of the H/T leads while the engine is running make sure you use a insulated pair of pliers as you could get a nasty kick from the electrics as there is quite a high voltage