Code P0431
Warm Up Catalyst Efficiency Bank 2
Plain English Meaning:Catalytic converter inefficiency on bank 2 during warmup
Yellow: Drive with Caution
Expensive repair likely
P0431 Symptoms
- •Check engine light emissions failure
Most Common Causes of P0431
P0431 Repair Playbook
Required Mechanic Tests
A qualified shop should perform these tests before replacing any parts to ensure they aren't guessing:
Check sensor readings
Typical Fix Paths & Estimated Costs
Replace converter $500–$2500
Parts for P0431 Repair
Common replacement parts for emissions codes. (Paid links)
🚗 Get Vehicle-Specific Search
Select your car to update the links above for a guaranteed fit.
Paid links — we may earn a commission. Please verify fitment details on the retailer site.
Fair Pricing Guides
Check our database for average parts, labor, and expected repair costs before heading to a mechanic.
🏷️ Current Catalytic Converter & Exhaust Coupons
8 live offersReal, current catalytic converter & exhaust coupons and discounts captured from national chains and repair brands. Updated automatically.
AAA Member Discount: 10% Off Parts & Labor (Up to $75 Off)National · works anywhere
Volkswagen of Downtown LA
Last checked Oct 10, 202610% Off Audi Service or Genuine PartsNational · works anywhere
Audi La Crosse
Last checked Oct 8, 202610% Off Repair Parts and Labor📍 94061
SpeeDee Oil Change & Auto Service
Last checked Oct 6, 202610% Off Parts & Labor (AAA Members)National · works anywhere
Honda of Downtown Los Angeles
Last checked Oct 4, 2026Rebate — money back after purchase$50 Mail-In Rebate on GM & ACDelco PartsNational · works anywhere
GM Parts / ACDelco
Last checked Oct 2, 2026AAA Member Discount (10% Off Labor & Parts)National · works anywhere
Subaru Santa Monica / AAA Approved Auto Repair
Last checked Oct 2, 2026AAA Member Discount - 10% Off Labor & PartsNational · works anywhere
Subaru Santa Monica
Last checked Oct 1, 2026Subaru Service Specials & Tiered DiscountsNational · works anywhere
Subaru Sherman Oaks
Last checked Oct 1, 2026
ServiceBuddy may earn a commission from some partner links, at no cost to you.