Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - View Single Post - O2 sensor question: which is before cat, which after

PantsDants · 01-12-2015, 02:28 PM

The one before the cat is actually an AFR sensor and costs a lot more. The one after is a standard O2 and costs less. I believe pre-cat is the gray plug and post-cat is black.

01-12-2015, 02:28 PM	#2
PantsDants Senior Member Join Date: Jul 2013 Drives: Scion FR-S A/T, Whiteout Location: Seattle Posts: 334 Thanks: 57 Thanked 221 Times in 90 Posts Mentioned: 16 Post(s) Tagged: 2 Thread(s)	The one before the cat is actually an AFR sensor and costs a lot more. The one after is a standard O2 and costs less. I believe pre-cat is the gray plug and post-cat is black.