P043E: EVAP reference orifice flow too low
Evaporative emission system leak detection reference orifice low flow
Severity: Monitor
P043E is an EVAP-monitor fault on cars with a leak detection pump and a reference orifice; it affects emissions rather than driving.
It gets more serious if:
- Inspect soon: Have it checked soon if the engine idles roughly, which Toyota lists with fuel in the EVAP system.
P043E in short
P043E means the computer found too little flow through the EVAP leak detection reference orifice, a tiny calibrated opening used to test the system. A clogged orifice, a faulty leak detection pump or canister problem is likely. On Toyotas it often appears with P2401 and P2419. A loose cap will not set it.
Cars with a leak detection pump measure flow through a very small reference orifice to check that the pump and system work. If the flow is too low, P043E sets.
PartsAvatar lists the EVAP pressure sensor, a clogged orifice, a ruptured canister, cracked lines and the leak detection pump. It says a loose cap will not cause this code.
Toyota TSB-0046-10 (cached summary) lists P043E with P2401 and P2419 and links the group to fuel in the EVAP system.
Most likely causes
Cause 1: Clogged leak detection orifice
Common general cause- Why it ranks here
- PartsAvatar lists a clogged or damaged orifice and charcoal contamination in it.
- What would change this
- Rises if flow through the orifice is low. Falls if it flows freely.
Cause 2: Fuel or charcoal in the EVAP system (some Toyotas)
Supported by vehicle data- Why it ranks here
- Toyota TSB-0046-10 lists P043E with P2401 and P2419 under fuel in the EVAP system.
- What would change this
- Rises if all three codes appear on a Toyota. Falls if only P043E is present.
Cause 3: Leak detection pump or EVAP pressure sensor fault
Common general cause- Why it ranks here
- PartsAvatar lists the pump, pressure sensor and pump module wiring.
- What would change this
- Rises if pump or sensor tests bad. Falls if they test good.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all codes, noting P2401 and P2419, and ask a dealer about EVAP bulletins.
IfP2401 and P2419 are also stored on a Toyota
It meansCheck the canister assembly.
IfP043E alone
It meansTest the orifice and pump.
Step 2: Have a shop inspect the orifice for charcoal contamination and test the pump and sensor.
Warning:EVAP lines hold fuel vapor; keep ignition sources away.
IfThe orifice is clogged
It meansClean or replace the assembly.
IfThe canister has fuel
It meansReplace the canister assembly.
Points to: Fuel or charcoal in the EVAP system (some Toyotas)
IfThe pump or sensor fails
It meansReplace it.
Points to: Leak detection pump or EVAP pressure sensor fault
Symptoms
- Check engine light
- Other EVAP codes at the same time
- Rough idle at operating temperature Gets more serious: stop and have it checked.
Compare with: Check engine light came on after getting gas
How to fix
Parts and cost context
- EVAP charcoal canister:Confirm with testing before buying. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
ToyotaYour car
2006–2010 · RAV4
Supported by vehicle dataToyota TSB-0046-10 lists P043E, P043F, P2401, P2402 and P2419 together with fuel in the EVAP system. Only the cached summary was read.
TSB-0046-10Status unverified
MIL on, fuel in EVAP system
2006–2010rav4 · NHTSA 10033407
Some vehicles show P043E, P043F, P2401, P2402 and P2419 with intermittent rough idle because of fuel in the EVAP system.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
01505Status unverified
MIL on, DTC P043E, P043F, P2401, P2402 and P2419
2005sequoia · NHTSA 10015869
Lists the same group of EVAP codes; summary does not state the repair.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
P043E questions
Will a loose gas cap set P043E?
No. PartsAvatar says a loose cap does not set this code; it needs a leak detection reference-orifice fault.
Sources and review
- P043E OBD error code summary
- P043E fault code entry
- Toyota TSB-0046-10: MIL on, fuel in EVAP system (P043E, P043F, P2401, P2402, P2419)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error