NOx Sensor 2 Circuit Performance
The POWERSTROKE-P229F (Power Stroke) diesel fault code means: NOx Sensor 2 Circuit Performance. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- intermediate
- Estimated cost
- $400-$1,200
Down with a Power Stroke fault on the road?
Get connected with a verified mobile diesel mechanic near you. Verified diesel & reefer techs, launching on the freight corridor.
Find a mobile mechanic →A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- CEL
- Derate
- Emissions system warning
Probable Causes (Ranked by Likelihood)
- Failed downstream NOx sensor Very Likely
- SCR catalyst failure Likely
- Harness fault Possible
Step-by-Step Diagnostic Procedure
Compare upstream vs downstream NOx readings at hot idle.
Replace downstream NOx sensor if values are nonsensical.
Frequently Asked Questions
What is P229F on a 6.7L Power Stroke (Scorpion)?
P229F on a 6.7L Power Stroke (Scorpion) (2011-present) indicates: NOx Sensor 2 Circuit Performance. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.
Can I drive with P229F on my Power Stroke?
Only drive short distances to get to a repair facility. Continued operation may cause further damage.
How much does it cost to fix P229F?
Repair cost is typically $400-$1,200 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.
P229F on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: