Car runs WORSE with O2's plugged in???
08-12-2007, 05:49 PM
#1
Car runs WORSE with O2's plugged in??? when I disconnect the harness from the O2 sensors the car runs better but not as smooth as it should be. When I plug the brand new O2's into the harness, the car runs alot worse. Alot more surging and bucking and it backfires too. I even took my 1 month old O2 sensors back and got another new pair and they do the same thing.
I took my car to the dealership and they said the O2s are working $80 for that
.
any one else ever have this problem? I feel the O2s are good and the problem is somewhere else.
I took my car to the dealership and they said the O2s are working $80 for that
.any one else ever have this problem? I feel the O2s are good and the problem is somewhere else.
08-12-2007, 06:26 PM
#2
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When the O2s are out the PCM faults them and reverts to open
loop. That may give you roughly-right fueling, it ought to anyway.
If the O2s are being fooled by cooling, excess air, etc. their output
may be worse than nothing at all, trim you to an over-rich situation
which is bad for idle, fuel economy, power, basically everything.
Headers are bad for this, especially uncoated ones. So are vacuum
leaks.
There's "good", and there's "good enough to still work in a non-
stock situation". You need to look at O2 output at idle with some
breeze under the car and see if they go to sleep after a little
while. They may work fine at cruise and just be for **** at idle
on account of the headers.
loop. That may give you roughly-right fueling, it ought to anyway.
If the O2s are being fooled by cooling, excess air, etc. their output
may be worse than nothing at all, trim you to an over-rich situation
which is bad for idle, fuel economy, power, basically everything.
Headers are bad for this, especially uncoated ones. So are vacuum
leaks.
There's "good", and there's "good enough to still work in a non-
stock situation". You need to look at O2 output at idle with some
breeze under the car and see if they go to sleep after a little
while. They may work fine at cruise and just be for **** at idle
on account of the headers.
08-19-2007, 02:31 PM
#7
Originally Posted by cerino2000
what's the backround on the car? Does it have a custom tune in it?
Ok story time:
I had the car dyno tuned and I asked my tuner how to get the car to cruise smoother and he told me to get new O2 sensors so I did. After we installed them, My tuner said one side was working and the other side was not. So after doing some searching I found the driver side harness had been kinked and 2 wires were cut. I soldered them back together and connected the O2s back up but the car ran worse.
I was told that I should have used regular connectors because the solder causes a resistance with the O2's. So I redid the wires with connectors and the car still ran like crap. I took the car to a dealership and paid them $80.00 to test the O2s and they said they were working.
I have been driving the car with the O2's disconnected. It still buck and surges but and does not back fire. With the O2's connected, the car runs worse with bucking and sometimes back fires.
The car idles fine and runs good at WOT but bucks alot while cruising. Im wondering if I need a part throttle tune???
