O2 sensor ? Necessary or not?
If you have a good tune that can get by in open loop
then no. If you've got unrealistic stuff in the tune (a
stock tune becomes unrealistic w/ mods) then trimming
may be needed to get it to run clean and (relatively)
tight.
Some people run open loop full time, on purpose. It's
not a bad way to go if you do it well and maintain it.
Of course the Smog Taliban have a different opinion.
then no. If you've got unrealistic stuff in the tune (a
stock tune becomes unrealistic w/ mods) then trimming
may be needed to get it to run clean and (relatively)
tight.
Some people run open loop full time, on purpose. It's
not a bad way to go if you do it well and maintain it.
Of course the Smog Taliban have a different opinion.
The only drawback to running permanently Open Loop is yopu now must adjust your fueling day to day if needed. Whereas if tuned properly the narrow bands could do this for you. Best thing to do if you want to run Open Loop constantly is to purchase a wideband to mount in your vehicle permanently so you can keep tabs on the fueling. Carb'ed cars have for the most part run Open Loop since the beginning. 
TECH Resident
Joined: Aug 2003
Posts: 970
Likes: 4
From: England UK
Originally Posted by 12secSS
The only drawback to running permanently Open Loop is yopu now must adjust your fueling day to day if needed. Whereas if tuned properly the narrow bands could do this for you. Best thing to do if you want to run Open Loop constantly is to purchase a wideband to mount in your vehicle permanently so you can keep tabs on the fueling. Carb'ed cars have for the most part run Open Loop since the beginning.
If you run open-loop with MAF that should adjust enougth for day to day changes in the weather. Works fine for me, been in OL-MAF for about 2 months now, fueling looks constant.
Thread Starter
On The Tree
Joined: Oct 2005
Posts: 161
Likes: 0
I've driven this car as my daily driver for about a year and 4000 miles now, I'm pretty sure my O2 sensors never have functioned and my Ed Wright tune seems to be perfect for all driving except emissions. I get no fuel smell at idle. I have awesome power at all rpms. I pass the 2200 rpm emissions with flying colors. I have 1700 ppm hydrocarbons at idle w/o cats (takes 220 to pass). I've now installed cats. I'm going to wrap them with some of that header wrap to keep them hot and do some tuning. I think I'll try emissions again and not install almost $300 worth of O2 sensors unless I can find a good reason to do it.
