P0420 / P0430 Fix for Ram 1500 5.7 HEMI

P0420 or P0430 on your HEMI? These catalyst-efficiency codes are a rite of passage on the 5.7 — they show up after headers, high-flow cats, or simply once the factory converters get tired. The truck drives fine; the light just won't leave.

The Fix: 90° O2 Sensor Spacer

The Brockett Built 90° O2 sensor spacer threads into the secondary (downstream) O2 bung, moving the sensor out of the direct flow so the PCM stops flagging cat-efficiency codes. CNC-machined, M18x1.5 thread — direct fit for Mopar downstream sensors.

• The HEMI has two banks — you need two spacers. P0420 = bank 1, P0430 = bank 2. The 2-Pack V8 Kit covers both.
• 10-minute install per side; clear codes and drive.
• Downstream sensors only — never the upstream pair.

Fits

Ram 1500 / 2500 5.7 HEMI (2003–present), Challenger and Charger 5.7/6.4, Jeep Grand Cherokee 5.7, Durango 5.7 — all M18x1.5 downstream threads.

FAQ

Will this clear my code for good?
Yes when the cause is low catalyst efficiency (mods or aging cats). Won't fix a bad sensor or exhaust leak.

Any tune needed?
No tuner, no flash — it's a bolt-on mechanical fix.

Legal note: designed for modified/off-road use — check 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.