before i ask questions heres the setup of my car
sorry for my poor english

98 civic
B18A1 motor stock just arp head studs
custom pieced turbo kit
plx wideband
precision 440cc
hondata s300

im not running any boost as of now

ive been street tuning couple of my cars with decentlyuntil now. low cam fuel map i am tuning.

i am just street tuning part throttle daily driving on my civic. i know that anytime you start tuning, you put your setting on open loop. i found my desired a/f ratio on my open loop from rpms 800-3000 to be around 14.2:1 - 14.7:1 on columns 2,3,4,5,6.

the problem is, when i put it back on closed loop, my a/f ratio that was tuned on open loop completely changes. my a/f on idle at open loop is roughly 14.3-14.7 but when i put in on closed loop it changes to 13.8-14.2

also daily driving on closed loop it will run very rich. it will vary from 10.9- 12.5 at times on light load. medium load it will be 13.1-14.3. is this normal on closed loop? but when i put it on open loop it will be at my desired a/f ratio 14.0-14.9 on light load and medium load

i am just waiting for my oil breather catch can and once installed, i will be tuning for boost. where i stay there is no dyno. i live on an island.

same car but different setup in the past didnt have this problem. i will tune on open loop and run on closed loop and the a/f ratio will be the way i want it to be 14.1-14.9


i just dont understand why? maybe my o2 is bad? can i just run on open loop mode all the time? also when i race do i have to put it on open loop? i never had this problem in the past. any help will be greatly appreciated. if you need more details please let me know

 

The issue could be your o2 sensor or your o2 feedback settings.

Personally I would just tune the car in open loop all of the time & just keep a wideband gauge in the car for monitoring purposes :-)

 

thank you very much. it is weird because the plx wideband does not have much usage on it. maybe 8 months the most.

i am thinking maybe the location of the o2 sensors are too far away. my stock o2 is located on my test pipe and the wideband is right before the collector of the downpipe.

my last setup was both only 5 inches away from the turbo outlet and i did notice it had faster response/reaction time on the gauge but i was thinking it was going to wear it out faster at the same time.

where can i check for the o2 feedback setting on my s300?

 

i also noticed that in open loop at idle my afr is around 14.5-14.7 and when i turn my headlights on it will richen to 14.2-13.8 and ill turn my blower motor on and it will richen some more to 13.5 afr

when i turn the headlights and blower motor off, it will lean back to 14.5-14.7 just the way it should be. anyone have any ideas?

 

Check your injector voltage compensation tables.

 

thank you will do. any other advice will be greatly appreciated.