The fuel system is a chain. Dirty fuel loads the filters. A restricted filter drops pressure. Low pressure makes injectors misfire. The ECM then logs codes that look like bad injectors or a bad module.
A sensible order of checks
- Drain water and replace both fuel filters.
- Check for air leaks on the suction side.
- Compare fuel pressure with the spec under load.
- Only then test individual injectors or the ECM.
In Dubai, stored fuel and dusty fill points make water and dirt common. A weekly drain of the separator is cheaper than a set of injectors. If you do replace injectors, fit new filters in the same job.
Send the codes and the engine serial together. A code list without the serial is only half the story.