Hi all round.
I have a Alfa 147 1.9 JTD 8V
About half a year back in service was cleaned EGR and intake manifold.
Everything was fine until about a month ago began to lose power range up to 2000rpm and from time to time between 1600-1900rpm was very appreciable drop in power for a very short time. All this set came in a lot of black smoke. About two weeks ago I found this forum and found instructions on cleaning the EGR. I decided that nothing is lost, and examine yourself whether it is functioning normally. I connected the PC to the ecu and P0404 error shown. When I took off the valve and separating it from the electrical parts in an attempt to push the mechanical parts turned out that it locks in the open position. Itself valve wasnt full of dirt. I do some cleaning and after about hour of soaking everything started working smoothly. I will put them all back, get tested it connecting the valve directly to the battery, everything worked perfectly. Will put them all together and put out the ECU error. Power at low revs was back. And the smoke disappeared. Everything was fine until the day before yesterday. Again appeared in the smoke, lost power. Again from time to time between 1600-1900rpm was very appreciable drop in power for a very short time. I connected the PC to the ECU but this time did not make any mistakes. Then I simply removed the EGR wiring and everything started working again. Of course now the ecu shows the error signal for the lack of egr but at least the car runs fine. What could be the problem?