FJCruiser rough running after fuel filter change

Sounds rough! I had a similar issue with my FJ. Same symptoms – check engine light, rough idle, felt like the engine was choking. Have you checked your fuel pressure? A pressure drop after changing the fuel filter could definitely point to a regulator issue or a leak somewhere in the fuel system. Also, have you checked the fuel pump?

Yeah, I checked the fuel pressure, and it's definitely lower than it should be. I'm just wondering if anyone knows if there's a common gotcha when changing the filter that could hose the regulator? Or could the fuel pump cause this?

In my case, the fuel pressure regulator was the culprit. I'd suggest taking it to a workshop; they should be able to diagnose it properly. It could be a faulty new filter or simply a coincidence that the regulator failed around the same time, but a professional diagnosis is always a good idea.

Thanks! Dropped it off at the shop. Turns out you nailed it – fuel pressure regulator was stuffed. They replaced it (45€), and it's running like a champ again. I guess I'll leave fuel filter changes to the pros from now on!