Nissan 370Z Forum - View Single Post

Alexwallace23 · 03-25-2017, 07:19 PM

Code P0420 popped up about 4 months ago after I got an oil change from Nissan. They cleared the code and the CEL stayed off until this morning. The only thing I did over the past couple days was clean the air filters on the Stillen long tube CAI. I cleared the code so that the CEL would turn off but the P0420 is showing up as a permanent code on the OBD scanner.

I have Berk HFCs installed. Could it be the HFC is going bad or maybe the O2 sensor?

Other upgrades:
Stillen exhaust
Motordyne manifold
UPRev Tune

All bolt-ons and tune were installed about 13,000 miles ago and I've never had a problem with this code or any other code prior to the oil change 4 months ago.

03-25-2017, 07:19 PM	#1 (permalink)
Alexwallace23 Base Member Join Date: Feb 2013 Location: Arizona Posts: 124 Drives: 2012 370Z Rep Power: 12	Permanent P0420 - Catalyst System Efficiency Below Threshold Code P0420 popped up about 4 months ago after I got an oil change from Nissan. They cleared the code and the CEL stayed off until this morning. The only thing I did over the past couple days was clean the air filters on the Stillen long tube CAI. I cleared the code so that the CEL would turn off but the P0420 is showing up as a permanent code on the OBD scanner. I have Berk HFCs installed. Could it be the HFC is going bad or maybe the O2 sensor? Other upgrades: Stillen exhaust Motordyne manifold UPRev Tune All bolt-ons and tune were installed about 13,000 miles ago and I've never had a problem with this code or any other code prior to the oil change 4 months ago. Last edited by Alexwallace23; 03-25-2017 at 09:16 PM.