TAMUz06

An exerpt from GM SI2000 Document #429151 states:

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">The catalyst monitor sensors operate the same as the fuel control sensors. Although the Bank 1 HO2S 2 and Bank 2 HO2S 2 sensors main function is catalyst monitoring, they also play a limited role in fuel control. If a sensor output indicates a voltage either above or below the 450 millivolt bias voltage for an extended period of time, the PCM will make a slight adjustment to fuel trim (FT) to ensure that fuel delivery is correct for catalyst monitoring </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I take this to mean that the rear O2's are used to determine the functionality of the cats. *IF* the return voltage from the rear O2's is off, it will adjust the fuel delivery accordingly to help bring them back in line. Placing O2 simms in place will return the proper voltage to the PCM and it will think everything is order.

Now, to my question - folks are "deleting the rear O2's" by simply masking the codes that are thrown by the rear O2's being out of whack - even though you no longer get the light, wouldn't the PCM still be trying to hinder the fuel delivery to compensate? If so, wouldn't the real solution be to just use O2 simms and be done with it, not touching anything within LS1 Edit?

<small>[ September 17, 2002, 07:08 PM: Message edited by: TAMUz06 ]</small>

chuckster

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TAMUz06:
<strong>An exerpt from GM SI2000 Document #429151 states:

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">The catalyst monitor sensors operate the same as the fuel control sensors. Although the Bank 1 HO2S 2 and Bank 2 HO2S 2 sensors main function is catalyst monitoring, they also play a limited role in fuel control. If a sensor output indicates a voltage either above or below the 450 millivolt bias voltage for an extended period of time, the PCM will make a slight adjustment to fuel trim (FT) to ensure that fuel delivery is correct for catalyst monitoring </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I take this to mean that the rear O2's are used to determine the functionality of the cats. *IF* the return voltage from the rear O2's is off, it will adjust the fuel delivery accordingly to help bring them back in line. Placing O2 simms in place will return the proper voltage to the PCM and it will think everything is order.

Now, to my question - folks are "deleting the rear O2's" by simply masking the codes that are thrown by the rear O2's being out of whack - even though you no longer get the light, wouldn't the PCM still be trying to hinder the fuel delivery to compensate? If so, wouldn't the real solution be to just use O2 simms and be done with it, not touching anything within LS1 Edit?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Actually I have O2 Sims and Gutted Cats.. I am still going to kill the COTS feature with LS1-Edit anyway. This actually dumps extra fuel into the system to cool down the cats if they get over a certain temp (derived from operating conditions not a temp sensor) This extra fuel will kill up to 15hp after 5000 rpm.

O2 Sims may be a great way to keep the system stable with or without cats...

But killing COTS with the CATS installed will eventually burn up your CATS...

TAMUz06

What is COTS?

Sonny

iTrader: (1)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TAMUz06:
<strong>What is COTS?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Cat OverTemp....in LS1 Edit v1.1.
Check your PM on TC.

<small>[ September 17, 2002, 11:47 PM: Message edited by: Sonny ]</small>