Good NBO2 in closed loop (i.e. trimming properly) will show these characteristics during steady part throttle:
- swinging faster than 2 complete cycles per second;
- swinging above 600 mV and below 300 mV;
- the average voltage will be close to 450 mV.
If they switch slower than 3 cycles per second, the the trimming will lag a little behind.
If they switch without going above 600 mV or below 300 mV then a DTC will trigger.
If the average mV deviates significantly from 450 mV then the trimming will be to some unknown AFR.
I find I have to replace NBO2's every 60K-70K miles... they do not go 100K as everyone believes.
Where at?
Sorry... I tried the "Reply With Quote" and screwed it up. I'm looking for the CALC.DYNAIRTMP formula previously posted. I have a 98 OS (F-Body)... just started reading this thread yesterday. Trying to learn everything about Calculated PIDs from scratch via hours of reading and safe experimenting. If you have a link to the actual formula that would be great.
Thanks
For OS id's 19980100, 1998020, 19980400 the pid GM.DYNAIRTMP_DMA is not defined... so you use CALC.DYNAIRTMP instead.
I updated Page 1 of the CALC.VET thread to support the 1997 Corvette and 1998 Camaro & Trans-Am, including the exact calc_pids.txt and Pids you must select:http://forum.efilive.com/showthread....l=1#post135867
Nice...Thanks
wow, I just put new o2s in and my trims went to positive 22% at idle. The other ones were less than a year old, less than 500 miles on them. The only reason I put them in was because at cruise I would get bank one having a like 1.6 positive trim and bank 2 was zero. I am logging the bank one 02 and it was fine before. I still get a deviance between banks, but i think the changes from this log will straighten it right up.
I guess goes to show you how different parts react. Should have it nailed down again after another log. I will post this one just so you guys can see what a difference it is. Remember that the last tune was spot on. Perfect trims, ect.. the only change was the o2 sensors.
Interesting.
Looks like the change was mainly at Idle. Rest of your log looks pretty decent.
I bet you get it straightened out in another log or two.
Thanks for the information..