Fuel is where money gets spent chasing a fault that is somewhere else. A running-lean or hesitation complaint should start with a pressure reading, not with a parts order.
Work in this order:
The OEM fuel pressure regulator covers 1996-2004 4Runner, Tacoma, T100 and Tundra. A genuine part, and the right answer when a diaphragm has failed — the classic sign being fuel in the vacuum line.
The AEM high-flow in-tank pump is a direct in-tank replacement with more capacity than the factory unit.
The honest guidance: a stock 3.4 does not need this. The factory pump is adequate for the factory engine and a mild one. Where it earns its place is forced induction or a built engine, where the extra fuel demand is real and a marginal pump shows up as a lean condition at exactly the worst moment.
The fuel filter covers 1988-2004 Pickup, 4Runner, T100 and Tacoma.
If you do not know when it was last changed, it is due. It is the cheapest part in the fuel system and a clogged one mimics a failing pump closely enough to get a pump sold to somebody who did not need it.
The Pro Fuel 5VZ hall sensor mount is part of an LC Pro Fuel installation — the bracketry that locates the crank trigger for a standalone system.
The Type E and Type F injector connector repairs the harness side, which is usually the real problem when one cylinder will not fire cleanly and the injector tests fine on the bench.
Diagnosing a fuel problem and not sure what the numbers mean? Send us the pressure readings and the symptoms and we will work it through with you.
