P0420 / P0430 Fix for Ford F-150 V8

Got a P0420 or P0430 catalyst-efficiency code on your F-150? On the 5.0 Coyote, 5.4 Triton, and 4.6 V8s this is one of the most common check-engine lights there is — especially after long-tube headers, high-flow cats, or once the factory cats age out. Truck runs strong, light won't quit.

The Fix: 90° O2 Sensor Spacer

The Brockett Built 90° O2 sensor spacer threads into the secondary (downstream) O2 bung and pulls the sensor out of the direct exhaust stream, so the PCM stops throwing catalyst-efficiency codes. CNC-machined, standard M18x1.5 thread — direct fit for Ford downstream sensors.

• V8 = two banks = two spacers. P0420 is bank 1, P0430 is bank 2 — get the 2-Pack V8 Kit.
• 10-minute install per side. Thread spacer into bung, sensor into spacer, clear codes.
• Rear (downstream) sensors only — never the front sensors.

Fits

F-150 4.6L / 5.0L / 5.4L (1997–present), plus Expedition, F-250/F-350 gas V8s, and Mustang GT with the same M18x1.5 downstream threads.

FAQ

Will it clear the code?
Yes, when the cause is low catalyst efficiency (exhaust mods or aging cats). It won't fix a dead O2 sensor or exhaust leak.

Does it affect performance or MPG?
No — downstream sensors only monitor the cat. Fuel trim comes from the front sensors, which stay untouched.

Legal note: designed for modified/off-road use — check your local emissions laws.

Get the 90° O2 Sensor Spacer — $42 single / $84 V8 2-Pack →

TIG-welded and machined by Brockett Built in central Illinois. Ships same or next business day. 30-day fitment guarantee.