I got a CE light on the way to the shop today, so I checked the codes and got

5 short 1 long 6 short

I am trying to figure out what this means but I cant for the life of me..

Logically, I'd guess

5 - Knock sensor (wtf?)
16- EGR valve (CA Only)


BUT.. On scuderia ciriani they say the codes may be reversed for the ones and tens (in order they display)... Which would be

51- Fuel pump relay
6 - Speedo Sensor

Fuel pump relay looks good, so I'm guessing the first set.. Does that make sense?

And do I even want to know how much a knock sensor is? Are they hard to install with the engine in/all accessories on the car?