Can new O2 sensors make your car run leaner/richer?
06-24-2006, 10:00 PM
#1
Can new O2 sensors make your car run leaner/richer? I recently had installed DENSO 3 wire heated O2 sensors in my LT1, replacing the single wire BOSCH sensors that my tune was done on.
The reason I did this is my 93 LT1 has a LT headers and a medium cam, 230/236 XE in a stroker motor.
The tune was very good before, just the idle was burning my eyes because it wouldnt stay in closed loop. The Heated O2's fixed this.
The dyno before was 425 rwhp 428 tq with 12.9 AFR and now with the new O2's its running 14 to 1 AFR!
Also, the second Dyno was different from the original and the Wideband was placed in the tailpipe of the second run (which had lots of balck smoke) while the first dyno was in the bung right after the colector, but no black smoke.
The reason I did this is my 93 LT1 has a LT headers and a medium cam, 230/236 XE in a stroker motor.
The tune was very good before, just the idle was burning my eyes because it wouldnt stay in closed loop. The Heated O2's fixed this.
The dyno before was 425 rwhp 428 tq with 12.9 AFR and now with the new O2's its running 14 to 1 AFR!
Also, the second Dyno was different from the original and the Wideband was placed in the tailpipe of the second run (which had lots of balck smoke) while the first dyno was in the bung right after the colector, but no black smoke.
06-24-2006, 11:55 PM
#3
Originally Posted by 35th SS
sup Steve.try search feature.good luck.see ya when the track reopens.
I ran good at BSMs ever time, then changed O2's which should only affect the idle, as it was the issue (real rich eye burning as it was in open loop). When at hypersports they showed it running lean 14 to 1 and it ws throwing all kinds of black smike out, with original tune and new one to compensate for the new O2's
06-25-2006, 12:37 AM
#5
Originally Posted by 35th SS
talked to brian or bode at the shop see what they say.
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06-26-2006, 01:50 PM
#8
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If your old sensors were fouled then the car would try
to learn anyway, swing to full positive trimming and
run rich in result. If they were only marginal, then it
might just affect the lower airflow cells. But locking
in those trims would enrich the WOT fueling, and
do it variably if the trimming indeed messed up only
some cells.
Putting new fresh ones would make it work better.
But if the preceding tune was trying to correct for
excess enrichment without fixing the cause, then
you could swing the other way once the rich trim
adder goes back down and quits meddling.
to learn anyway, swing to full positive trimming and
run rich in result. If they were only marginal, then it
might just affect the lower airflow cells. But locking
in those trims would enrich the WOT fueling, and
do it variably if the trimming indeed messed up only
some cells.
Putting new fresh ones would make it work better.
But if the preceding tune was trying to correct for
excess enrichment without fixing the cause, then
you could swing the other way once the rich trim
adder goes back down and quits meddling.
06-26-2006, 04:11 PM
#9
Originally Posted by jimmyblue
If your old sensors were fouled then the car would try
to learn anyway, swing to full positive trimming and
run rich in result. If they were only marginal, then it
might just affect the lower airflow cells. But locking
in those trims would enrich the WOT fueling, and
do it variably if the trimming indeed messed up only
some cells.
Putting new fresh ones would make it work better.
But if the preceding tune was trying to correct for
excess enrichment without fixing the cause, then
you could swing the other way once the rich trim
adder goes back down and quits meddling.
to learn anyway, swing to full positive trimming and
run rich in result. If they were only marginal, then it
might just affect the lower airflow cells. But locking
in those trims would enrich the WOT fueling, and
do it variably if the trimming indeed messed up only
some cells.
Putting new fresh ones would make it work better.
But if the preceding tune was trying to correct for
excess enrichment without fixing the cause, then
you could swing the other way once the rich trim
adder goes back down and quits meddling.
On the other hand, is there a learn time for 93 ECMs after putting a new tune in it? Its been a while and a few hundred miles.
06-28-2006, 09:24 AM
#10
On this link are my dyno AFR graphs
Steves dyno and these are with heated O2's and DELTEQ, and the videos are from other cars there.
here is my old dyno graph across town.
Steves dyno and these are with heated O2's and DELTEQ, and the videos are from other cars there.
here is my old dyno graph across town.
