Wrong O2 sensor position in almost all headers! - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

JIM THEO · 08-30-2018, 03:59 PM

Did I say performance anywhere?
If I move the front O2 sensor to other position it will be only for engine protection not for performance.
And to go further the discussion every O2 sensor, even the second one, shouldn't be horizontally.
Humidity from the exhaust gases when you turn off the engine will destroy it in the long term use!

If you ask me the header you posted is not "right" at least for my needs (low-mid torque, torque dip elimination, driveability), IF I had to extract the last horse of my BRZ I'd buy an ACE header not one as the above nor the Gruppe-S, but thanks anyway!

guybo · 09-01-2018, 12:05 PM

IMHO this is another reason to gut the OEM header. It's a well designed EL header with great heat shielding. I'd rather have the O2 sensor sniffing all 4 cylinders because if I get something like an injector stuck wide open, or a cylinder going dead lean from an injector getting clogged, there's only a 1 in 4 chance of that aftermarket header catching it.

I run an aftermarket AFR sensor anyway (for E85 without a FFK) but the OEM set up is well designed.

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08-30-2018, 03:59 PM	#15
JIM THEO Senior Member Join Date: Feb 2018 Drives: BRZ 2018 Location: Greece Posts: 498 Thanks: 119 Thanked 142 Times in 99 Posts Mentioned: 6 Post(s) Tagged: 0 Thread(s)	Did I say performance anywhere? If I move the front O2 sensor to other position it will be only for engine protection not for performance. And to go further the discussion every O2 sensor, even the second one, shouldn't be horizontally. Humidity from the exhaust gases when you turn off the engine will destroy it in the long term use! If you ask me the header you posted is not "right" at least for my needs (low-mid torque, torque dip elimination, driveability), IF I had to extract the last horse of my BRZ I'd buy an ACE header not one as the above nor the Gruppe-S, but thanks anyway!

09-01-2018, 12:05 PM	#16
guybo Huge E85 fan! Join Date: May 2016 Drives: 2016 Scion FRS Location: Tampa, FL, USA Posts: 1,850 Thanks: 539 Thanked 1,010 Times in 605 Posts Mentioned: 32 Post(s) Tagged: 0 Thread(s)	IMHO this is another reason to gut the OEM header. It's a well designed EL header with great heat shielding. I'd rather have the O2 sensor sniffing all 4 cylinders because if I get something like an injector stuck wide open, or a cylinder going dead lean from an injector getting clogged, there's only a 1 in 4 chance of that aftermarket header catching it. I run an aftermarket AFR sensor anyway (for E85 without a FFK) but the OEM set up is well designed.

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