failure

I have a problem with a 2001 Chevrolet Astra with a 2.0 8v engine. When I accelerate hard, like when I'm trying to get it moving, it hesitates and backfires through the air filter. I've already replaced several sensors and actuators thinking that was the problem, but it keeps doing the same thing. The only other thing I've noticed after everything I've changed is that the spark plugs aren't burning evenly; one side burns well, and the other side comes out black. If anyone has experienced something similar, I would appreciate any help in finding the problem

Have they not distributed it yet?

That's right, first check the timing. If it's running well and backfiring through the intake, which is what you're saying, the problem is electrical. Check the wires, coil, and spark plugs, as well as the condition of the injectors.

What fault codes are you getting? You need to scan it. Check the MAF sensor

You need to check the ignition and fuel pressure. You might have low fuel pressure.