Hi.
Few months ago i bought 1987 econoline E150 with 4.9 l6 engine, driven 67k miles.
I'm converting it into offroad campervan btw : )

Just got innova code reader, which
I plugged while the engine was running (koer self test) and the first code is suppose to show how many cylinder engine it is. It shows 4 instead of 6... Does it mean that 2 cylinders are not firing? It has a rough idle...

I got new spark plugs and wires, which i will change later. Going to take the engine out of the van to clean it, repaint and change gaskets, clean fuel injectors etc. Just want to know if I can expect something worse than bad spark plugs...

Anyone had the same issue and code?
got also code 42, 33 and 52 btw, but not sure that's causing this...

 

It is possible there is a problem with the EGR system. 52 was most likely because you did not move the steering wheel in both directions at the time you were doing the test.
The EGR valve and passages may be loaded with carbon and need to be cleaned and the sensor on top of the EGR valve may be malfunctioning.