P2293: Fuel Pressure Regulator B Performance
What to do
Expect hesitation, rough running or reduced power, often worst during changes in throttle. Ask for the fuel supply and filter to be checked before the regulator is replaced — a regulator asked to hold a pressure the supply cannot deliver fails this test while being perfectly good, and a filter is a far cheaper repair.
What this code means
The second fuel pressure regulator is not achieving the pressure it was commanded to.
Why a fuel system has two regulators is worth setting out, because which one is faulted says which side of the pump the problem is on.
A modern high-pressure fuel system usually controls pressure in two places. One valve meters how much fuel is allowed into the high-pressure pump — controlling supply before compression. A second valve bleeds excess out of the rail — trimming pressure after compression. The reason for both is efficiency and heat: compressing fuel and then dumping it wastes the energy spent compressing it and warms the fuel doing so, so the inlet valve does the coarse work and the rail valve makes the fast, fine corrections.
That division has a diagnostic consequence. The rail-side regulator is the one that responds quickly, so faults there show up as pressure that will not settle, or that lags behind demand during throttle changes — rather than as a system that cannot reach pressure at all, which points at the inlet side or the pump.
Before the valve itself, the usual suspects apply and are cheaper: a restricted filter or weak lift pump starves the high-pressure pump, and a regulator commanded to hold a pressure the supply cannot support fails its performance test through no fault of its own.
Likely causes
Start here
- Faulty fuel pressure regulator · moderate
- Restricted fuel filter · easy
- Weak fuel pump · moderate
Less common
- Faulty fuel rail pressure sensor · moderate
- Worn high pressure fuel pump · specialist
- Air drawn into the fuel supply · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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