how would the car run if i unplugged the front o2's?

how would the pcm calculate the a/f ratio?

 

There is an open loop A/F table in the PCM.

It would just stay in open loop and use the A/F tables in the PCM to calculate the injector pulse width. Btw, the A/F tables are only used in open loop. If your tables are still stock then it may run like crap. They are "just" numbers and to not refect the actual A/F ratio though. Change them to richen or lean out the car at the various ranges. You are going to need a wideband to do this.

 

the car runs horrible at part throttle (missing/surging/hesitation) and idles low after a neutral rev and then returns to normal....

i was thinking it might be my o2's, i might unplug them and see how it runs....

 

i swapped my stock TB back in for the POS bbk 58 TB and the idle problem is gone....

although the car still misses after it warms up....runs good cold...

 

i unplugged my front 02's and my miss/surge/hesitation is completly gone now....at all operating temps.

i ran the car for about an hour before i got a SES...


i guess that would mean my oxygen sensors are bad right?
i have BOOSCH about 1 year old....

what else could it be? it only seems to miss once the car is in closed loop, what other sensors come "alive" in closed loop?

thanks
jesse

 

i had the car scanned today at the dealership. i reconnected the o2 sensors.
the car had thrown 3 codes:
1. left bank Ho2s circuit
2. right band Ho2s circuit
those were a given because i unplugged the o2s
3. MAF ciruit code 48
we cleared all the codes

the car once again ran great, no miss at all (in open loop)
as soon as the car goes into closed loop the surging/hesitation was back....
the o2 readings were fairly equal
cruise speed in OD readings were .500's
partial acceleration in Drive the readings dropped to the 400's

WOT readings were in the 800's

do the partial acceleration reading seem low?

well now i dont think the 02s are the problem.....

im going to swap a buddies MAF sensor in see what happens

any ideas?

thanks
jesse