P1604Fuel & Air Metering

Startability Malfunction (Toyota/Lexus)

P1604 is a Toyota/Lexus code for a startability malfunction, meaning the engine had trouble starting or nearly stalled during startup. It is often tied to fuel, ignition, or idle control issues.

🚗 Yes, but expect hard starting or stalling right after startup.

MEDIUM

severity

🎯 Top Causes, Ranked by Likelihood

#1Weak fuel delivery or dirty injectors$50-$400

40%

Poor fuel delivery makes cold starts difficult.

#2Ignition weakness (coils/plugs)$50-$400

25%

Weak spark causes rough or hard starts.

#3Idle air control or vacuum leak$50-$300

20%

Poor idle control or leaks cause near-stall on startup.

#4Battery or charging weakness$100-$300

15%

Low cranking voltage contributes to hard starts.

🩺 Common Symptoms

Hard starting
Stalling shortly after start
Rough idle at startup
Check engine light

💰 Repair Cost: DIY vs Shop

DIY Cost

$50-$400

Shop Cost

$150-$600

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose P1604

1Inspect spark plugs and ignition coils

2Check fuel pressure and injector operation

3Look for vacuum leaks affecting idle

4Verify battery and charging system health

❓ Frequently Asked Questions

Can I drive with P1604?

Usually yes, but expect hard starts or near stalls. Diagnose the root cause soon.

Is P1604 a Toyota code?

Yes, P1604 is a Toyota/Lexus startability malfunction code.

What causes P1604?

Weak fuel delivery, weak ignition, idle control issues, or a vacuum leak are common causes.

🔗 Related Codes

P1605P0300P0505