P0420 / P0430 Fix for Nissan Frontier, Xterra & Pathfinder

The 4.0L VQ40DE V6 in the Nissan Frontier, Xterra, and Pathfinder is one of the most notorious engines for throwing P0420 or P0430, usually from an aging factory cat that still runs fine but trips the light, or after a high-flow exhaust. Before you drop $700 or more on new cats, this is the part to try first.

The Fix: 90° O2 Sensor Spacer

The Brockett Built 90° O2 sensor spacer threads into the downstream (rear) O2 bung and moves the sensor out of the direct exhaust stream, so the ECU reads a clean signal and stops throwing the catalyst-efficiency code. CNC-machined for the M18x1.5 thread, a direct fit for Nissan downstream sensors.

• The VQ40 is a dual-bank V6, so you may need two spacers. P0420 only means one; P0420 plus P0430 means two. Grab the 2-Pack and save.
• About a 10-minute install per side. Clear codes and drive a readiness cycle.
• Downstream (rear) sensors only, never the upstream sensor.

Which Models Fit?

• Nissan Frontier (2005+): 4.0L VQ40DE V6
• Nissan Xterra (2005-2015): 4.0L VQ40DE V6
• Nissan Pathfinder (2005-2012): 4.0L VQ40DE V6

All use the standard M18x1.5 downstream O2 thread.

FAQ

Will it affect performance or fuel economy?
No. The downstream sensor only monitors cat efficiency, it doesn't control fuel trim, so your tune and mileage are unaffected.

Will it clear the code for good?
Yes, if the P0420 or P0430 is from a lazy or aging cat or a high-flow exhaust. It won't fix a code caused by a bad O2 sensor or an exhaust leak.

Legal note: designed for modified/off-road use. Check local emissions laws.

Get the 90° O2 Sensor Spacer: $42 single / $84 2-Pack →

Machined by Brockett Built in central Illinois. Ships same or next business day. 30-day fitment guarantee.