failure

1. Check the camshaft position sensor:
a. Initially disconnect it and reconnect it.
2. Check the fuel pressure at the fuel rail. (Do this last.)
3. Disconnect one of the high-voltage spark plug wires, then:
a. Ground it to the engine block.
b. Then try to start the engine.
c. Observe if there is a spark
4. Try connecting a scanner to find out what fault codes it throws. Let me know if you have any questions. Cheers.

The spark plug issue is puzzling. Could you have an air leak in the intake manifold? The backfires could be caused by a lean fuel mixture (due to unmetered air entering the engine), and the spark plugs could be very black. The acceleration problem could stem from the fact that, because of the excess air, the lambda sensor is detecting a lack of fuel and enriching the mixture, which negatively impacts the cylinders that don't have excess air.

Check your intake manifold gaskets; if they're sucking in air, cold air can enter the combustion chambers and cause backfires. It wouldn't hurt to check them. Good luck.

First of all, check the mechanical issues. If your car has two oxygen sensors before the catalytic converter, you should check if either of them is causing the fuel mixture to become too rich. If all of this is okay, take it to someone who has the original scanner (Tech2) to have them perform a full trim adjustment.

Thank you all for your input, but I've checked almost everything. I'm a mechanic, and I already used a Tech 2 diagnostic tool. The code that was showing up was for the TPS sensor. I checked it, and one of the wires had been removed—I don't know why—but I reconnected it properly, and it cleared the fault code, and now no other codes are showing up. I've already checked the fuel pressure, and it's fine. I even tried a new fuel pump, and nothing changed. I've also tried another ignition coil, MAP sensor, TPS sensor, and IAC valve. I loosened the exhaust pipe thinking it might be clogged. I checked the timing twice to make sure it was aligned correctly, and nothing. I don't think it's sucking in air because it would be running rough at low speeds or when accelerating hard, and it's not doing any of that. It only misfires when I floor it