Bogging

andy

Alright so yesterday I was at my friends house for six hours tryin to fix his 93 ex its bogging hella bad
we put new plug wires on and replaced the distributer cap when we took the distributer cap off it was full of white dust so we cleaned it out real good, so we started it up and the car ran freakin perfect like fresh off the lot, til about 11pm  we went to leave and it started bogging hella more than it did he was flooring it and it was struggling to reach 3k
anyone have any idea why it would run perfect and then break aluva sudden????

.try replacing the O2 sensor.