2004 Toyota PriusFACTORY OEM SERVICE PROCEDURE

Service Data

Emission Control Service Data Specification

Air-fuel ratio sensor    
Voltage E5-23 (A1A+) - E5-28 (E1) 3.0 to 3.6 V
  E5-22 (A1A-) - E5-28 (E1) 2.7 to 3.3 V
Resistance 1 (HT) - 2 (+B) 1.8 to 3.9 Ω at 20°C (68°F)
  2 (+B) - 4 (AF-) 10 kΩ or higher
Vapor pressure sensor    
Voltage 1 - 3 4.5 to 5.5 V
  2 - 3 3.0 to 3.6 V
Vacuum switching valve assy No. 2    
Resistance 1 - 2 26 to 30 Ω at 20°C (68°F)
Charcoal canister vacuum switching valve    
Resistance 1 - 2 36 to 42 Ω at 20°C (68°F)
Trap w/ outlet valve canister assy    
Resistance (VSV for CCV (canister closed valve)) 1 - 2 25 to 30 Ω at 20°C (68°F)
    32 to 40 Ω at 100°C (212°F)
Heated oxygen sensor    
Resistance 1 (HT) - 2 (+B) 11 to 16 Ω at 20°C (68°F)
  1 (HT) - 4 (E) 10 kΩ or higher
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.