1. I recently pulled my injectors out an upon inspection I found that the upper intake manifold has a lot of black build up. I want to clean it out, how do I do this?

2. Should I port the intake manifold while its off?

3. The injector holes are filled with carbon deposits, how do I clean this?

4. This is BIG question. My car runs like crap, stalling and hesitation all day. I tried adjusting some of the sensors and cleaning some others, and it runs a little better. Is there any way I can scan the ecm to test what sensors are not working and need replacing? I heard there are some programs I can hook up on my laptop to read the ecm? What would I need to this, cable and program? Is my car an OBD1 or 2.

Any help would be greatly appreciated.