Off Road Pipe O2 Sensors performance?
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Teching In
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Off Road Pipe O2 Sensors performance? I just installed some pacesetters headers, off road Y pipe and hooker catback exhaust. For the front 02 sensors i used some extensions. For the rear 02 sensors (the one in the cats) were eliminated. I understand that this will cause my check engine light to be on, but will it affect performance?
I was under the impression that the front 02 sensors are the ones who controlled the fuel/air mix and the rear just monitored and should not affect performance. what are you guys using?
I was under the impression that the front 02 sensors are the ones who controlled the fuel/air mix and the rear just monitored and should not affect performance. what are you guys using?
The rear O2 fuel trim function needs disabled, not just the codes shut off. Amazes me how many think you just shut the codes & COT mode off. Shutting the codes off will get rid of the light.
Joined: May 2004
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From: Halfway back on the Highway to Hell...again!
The rears do not affect performance. that only tells you that a cat is not doing it's job correctly. EPA smog garbage!!!
But it's definately something you want tuned out. If the CEL is always on, then something really does go wrong, you won't know it. Unfortunately, O2 sims are a thing of the past since everyone now just tunes out the rear O2's. They just used to plug right in and send a good signal to PCM. Now they are obsolete or very expensive if you can find them.
But it's definately something you want tuned out. If the CEL is always on, then something really does go wrong, you won't know it. Unfortunately, O2 sims are a thing of the past since everyone now just tunes out the rear O2's. They just used to plug right in and send a good signal to PCM. Now they are obsolete or very expensive if you can find them.
The rears do not affect performance. that only tells you that a cat is not doing it's job correctly. EPA smog garbage!!!
But it's definately something you want tuned out. If the CEL is always on, then something really does go wrong, you won't know it. Unfortunately, O2 sims are a thing of the past since everyone now just tunes out the rear O2's. They just used to plug right in and send a good signal to PCM. Now they are obsolete or very expensive if you can find them.
But it's definately something you want tuned out. If the CEL is always on, then something really does go wrong, you won't know it. Unfortunately, O2 sims are a thing of the past since everyone now just tunes out the rear O2's. They just used to plug right in and send a good signal to PCM. Now they are obsolete or very expensive if you can find them.
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From: Halfway back on the Highway to Hell...again!
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From: Halfway back on the Highway to Hell...again!
I used mailorder and made my own adjustments for the transmission shift points. I left the other stuff to the pros. The only thing is yours is a 97 OBDII. So there might be more to than what all I've told you. Just make sure, if you do send your PCM to someone, they don't "lock it". I had that happen by a tuner, ONCE!!! Never again!!
Last edited by SAPPER; Jan 22, 2013 at 03:25 PM.
I make no claims like that.
I do, however have the actual printed listing for those (and many other) PCMs which (the OBD1 LT1, and the OBD2) fills up two loose leaf note books each, came right out of GMs back door. Everything in those two flash chips, giving the location in the binary files, the meaning, and how everything is calculated. The plug-in chips only require one notebook each.
Helps to have connections. :-)
I do, however have the actual printed listing for those (and many other) PCMs which (the OBD1 LT1, and the OBD2) fills up two loose leaf note books each, came right out of GMs back door. Everything in those two flash chips, giving the location in the binary files, the meaning, and how everything is calculated. The plug-in chips only require one notebook each.
Helps to have connections. :-)
TECH Veteran
Joined: Dec 2008
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From: Little Rock, AR
It is probably little known or read, but it is stated in the factory manual that the rear O2s will play a limited role in fuel management if situations occur that hamper the sensors ability to monitor catalyst function. Therefore, you could likely conclude that there are some tables or switches in the PCM that correspond to that role as Ed noted.
There are probably few people that know more of what is inside that PCM than Mr. Wright.
There are probably few people that know more of what is inside that PCM than Mr. Wright.
Joined: May 2004
Posts: 1,593
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From: Halfway back on the Highway to Hell...again!
I do not doubt his knowledge and abilities. I also know he's been actively involved since the creation of the LT1. I've used just about every tuner out there since I bought the car new in 94, as well as dyno tunes. I like to experiment. WTH, it's only money and worth it for knowledge.
My list includes:
Fastchip (Ed), PCM for less, Madtuner, Street&Performance and 4 different dyno tuners. I even tried the Hyperjunk thing. Garbage!!!
This was all done during a stock motor set to the hotcam kit.
1 dyno tune was so far off, I had to trailer the car home and had to reload a previous tune. The idiot didn't even save the original tune in the car before he started. He didn't get paid and almost got a ride to the morgue.
My list includes:
Fastchip (Ed), PCM for less, Madtuner, Street&Performance and 4 different dyno tuners. I even tried the Hyperjunk thing. Garbage!!!
This was all done during a stock motor set to the hotcam kit.
1 dyno tune was so far off, I had to trailer the car home and had to reload a previous tune. The idiot didn't even save the original tune in the car before he started. He didn't get paid and almost got a ride to the morgue.
