Hello friends, I'm posting here an image of the pressure transducer installed in the cylinder number 1 of the civic 1.7 16v engine, looking at the image of the tdp, I would soon think of a clogged catalyst due to the elevation there in the exhaust phase or as we call the exhaust table, I found it very strange to raise only one side of the scission phase at the end of the admission phase, and this led me to advance in the tests, I did the following test, I removed the probe o2 and reconnected the motor and doing this the waveform stabilized normal and an important detail of that and that when I went to check the catalyst had been withdrawn in another workshop, to go deeper in the test I reinstituted the probe and removed the exhaust dampers and soon the form of wave became normal, summary defect was the secondary damper obstructed by the debris of the primary damper that was the cause of all defect.