1993 945T around 173k miles.

Car all of a sudden lost much power on highway, Check Engine light came on, and it was only able to maintain 20mph speed. Pulled over and waited about 30 minutes. Car then started right up. I shut it down before pulling code in Mode 1. Socket 2 gave 1-1-1, but socket 6 gave 1-4-4. Check the code table and it says:

- 1-4-4*
- No load signal from fuel injection system
- Faulty wiring from LH to EZK; bad LH module 
- Engine lacks power; stalls; doesn't start or is jerky

Elsewhere in the 7xx/9xx FAQ I found this:

"These same symptoms, though, can also be caused by a defective fuel pressure regulator, a plugged fuel filter, dirty fuel injectors, a restriction in the fuel supply line, a leaky pump check valve,  or a dirty filter sock in the tank."

I think the fuel filter must be changed first. Haven't done that since I bought the car used. My question is: "Am I on the right track?"

Much thanks,
Lih-Yen