open loop
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,159
Likes: 31
From: Orange Park Florida
open loop
After replacing full exhaust system with ceramic hooker long tubes with emission tubes. and leaving all the air pump stuff intact, minus the cats of course. My wife says she smells exhaust fumes, personally I can't smell them since I lost most of my sense of smell from my brain injury when I was ran over at work.
Does anyone know of a check that I could do to determine if I am going into closed loop?? I did put new connectors on the O2 sensor and installed a heated O2 sensor.. I did have a issue with the 12v switched feed to the sensor... but the o2 sensor is so high on the header tube that I questioned even needing a heated sensor. thanks for any help, Gary
Does anyone know of a check that I could do to determine if I am going into closed loop?? I did put new connectors on the O2 sensor and installed a heated O2 sensor.. I did have a issue with the 12v switched feed to the sensor... but the o2 sensor is so high on the header tube that I questioned even needing a heated sensor. thanks for any help, Gary
Thread Starter
Burning Brakes
Joined: Nov 2008
Posts: 1,159
Likes: 31
From: Orange Park Florida
Roger that
Roger that, and thanks for the reply.. it runs really good with the new exhaust system.. and no codes at all have come up since the install.. thought about installing the air line from the air pump to add some additional air to the exhaust,, or maybe a hi po cat?? thanks, gary
Last edited by gman35; May 25, 2015 at 10:10 PM. Reason: typo error
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
If you have a pre-1990 car (you didn't tell us the year), you can tell if it's in open or closed loop by shorting the A & B contacts together in the ALDL connector AFTER the engine is running. If it's in open loop mode the Service Engine Soon light will flash at 2-1/2 times a second. If it's in closed loop mode it will flash once per second.
Team Owner
Joined: Dec 2000
Posts: 21,094
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From: Phila., PA burbs
If you have a pre-1990 car (you didn't tell us the year), you can tell if it's in open or closed loop by shorting the A & B contacts together in the ALDL connector AFTER the engine is running. If it's in open loop mode the Service Engine Soon light will flash at 2-1/2 times a second. If it's in closed loop mode it will flash once per second.
Safety Car
Joined: Jun 2003
Posts: 4,250
Likes: 656
From: San Diego Ca
Adding LTs without a tune and it will be running rich....particularly at idle. Simply take it in for a tune. However you will get unburned HC out the exhaust so that will always smell and is a dead giveaway to a car without cats, as the bumper fascia above the exhaust tips gets black.
Team Owner
Joined: Sep 2001
Posts: 62,153
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
The best way is to do the SES light trick above or drive it around with a scanner hooked up. The scanner will tell you when it drops back into open loop mode, which will probably only be at idle.
A tune will help, but it is not strictly necessary, nor is a heated O2 sensor.
A tune will help, but it is not strictly necessary, nor is a heated O2 sensor.
