Nissan Sentra 2001 Slut

Hello everyone, I have this little problem with this car, it works very well on low but when you are already driving it, it begins to rattle in any situation that demands a little strength to the engine ..
the car is automatic

hello good evening.
I would like to answer first with another question. Have you done any kind of inspection or repair so far?
If it is not doing an empty acceleration test without marching if this is positive inspects the ignition system, a spark plug, cable, rotor or distributor cover, this causing the problem.
luck....

How about Victor, thanks for answering the question.
And based on your question, if I just changed the ECU to this car, since the ECU had damaged the exits that send pulses to the coils. But I already had the problem of the bell.
Well, after performing several tests that you indicated, we found that there is a problem with the compression on the pistons and we believe that this is the raiz the problem of the problem, since it is quite the difference between the pistons
piston 1 140Psi
Piston 2 140Psi
Piston 3 70Psi
Piston 4 50Psi
Thank you, I hope that this information serves someone else.
Thank you all.

Hello, surely because of the data you contributed in the post you have the joint (packaging) of cylinders burned between the cylinders that have less compression, it means that the car has already been working with the ignition out of point (advance of lighting on the high.