Checks, in order
- Read all codes togetherNote sensor heater, misfire and fuel trim codes alongside the catalyst code. Fix the underlying ones first because they can cause the catalyst code.easy $ · under about $50
- Exhaust leaks near the sensorsCheck the manifold, flex joints and gaskets for leaks with the engine cold. Air getting in skews sensor readings.easy $ · under about $50
- Air/fuel sensorsWatch live data for slow or stuck readings and replace a sensor that is lazy or has a heater code. Use the correct Toyota-spec part for the bank and position.medium $$ · about $50 to $500
- Secondary air systemIf the code is P2440 or P2442 on a truck that has it, check the pump, valve and hoses for moisture or damage. Ask a dealer whether a service bulletin applies to your VIN.medium $$ · about $50 to $500
- Catalytic converterReplace only after the above checks pass and the downstream sensor mirrors the upstream. Use a compliant converter, since some states require specific parts.medium $$$ · shop-level job, $500+
Applies to: 2005 to 2015 Tacoma with the 2TR-FE 2.7L four-cylinder and 1GR-FE 4.0L V6, 2WD, PreRunner and 4WD. Both engines use timing chains and a serpentine-belt-driven water pump.
Tools and parts for these checks
Links below are Amazon affiliate links: as an Amazon Associate, toyotadata earns from qualifying purchases, at no extra cost to you. Confirm fitment for your exact truck before you order.
| ITEM | USED FOR | BUY |
|---|---|---|
| Bluetooth OBD2 scanner with live data | Reading and clearing codes and watching live sensor data | Shop on Amazon |
| Downstream oxygen sensor | Replacing a lazy rear O2 sensor before condemning the converter | Shop on Amazon |
More 2nd Gen Tacoma problems
- Frame rust: flaking, holes or a soft frame (Frame & Body)
- Rear sag, squeaks or a cracked rear leaf spring (Steering & Suspension)
- Clunk, knock or rattle going over bumps (Steering & Suspension)
- Steering feels stiff, rattles or wanders (Steering & Suspension)
- Shaking, shimmy or violent wobble at highway speed (Steering & Suspension)
- Humming or rumbling from the front that changes with speed (Front Axle)
All 16 2nd Gen Tacoma symptoms in the interactive troubleshooter →
General guidance from owner experience. Confirm torque specs, fluid capacities and procedures in the factory service manual. Brakes, steering and anything structural: if in doubt, have a qualified shop inspect it before driving.