Tuning and O2 sensor

[Frostbite545]

Ok so my current modifications are listed in my sig. I plan on getting SS headers, but not for a while. Ever since I put the exhaust on, my SES light has been on constantly, only went off once long enough to get it inspected, but its back now, and annoying me. Apparently its the second O2 sensor, near the cat, so theres no performance or gas milage being affected, but I want it taken care of, ( I mean, if something else goes wrong theres no way to know, if the light is always on.)

Talking to some friends, I see my options as: an O2 simulator, a wide band 02 sensor, or take it to the dyno and have them tune it and hopefully change the parameters to have the computer accept the 02 readings.

Which of those do you think will work, which wont, and are there better options (besides buying the tuner and doing it myself) ?

[Gr1m]

replace the sensor for now until you get your headers, then get a o2 sim i would say

[MixtapeMessiah]

if you just want to get rid of it completely, get urself hp tuners, disable the downstream o2 sensor via hp tuners and reset ur dash lights and bingo problem gone.

And with the hp tuners u can tune it for later mods u do to the car, just my 2 cents.

[Frostbite545]

replace the sensor for now until you get your headers, then get a o2 sim i would say

Would it matter when I get the O2 sim ? If I get it now and get headers will I have to change it up or something ?

[jackal2000]

might as well get the sim now if you dont plan on ever tuning your car. last i checked, hp tuners does not support the the GM v6 crowd, Digital HP does.

[Redog]

You'll have to get the sim now.

The downstream sees more flow due to the cat being changed. The 2 O2's tell each other how much fuel to dump. Since the downstream isn't working properly, the upstream will just dump more fuel, wasting gas, and burning up the cat in the long run

[jackal2000]

no, the sole purpose of the downstream O2 is to make sure the cat is working and therefore it is worthless in regards to performance which is why i (and many others) dont have one. it was easier for me to delete the codes for it and not have the exhaust guy weld a bung into the end of the cat for it than to keep it and deal with SES lights.

[BlackJack]

Would it matter when I get the O2 sim ? If I get it now and get headers will I have to change it up or something ?

The downstream (2nd) O2 sensor only detects if your cat is working. The first one (on your exh manifold or header) is what helps regulate mixture.

might as well get the sim now if you dont plan on ever tuning your car. last i checked, hp tuners does not support the the GM v6 crowd, Digital HP does.

TurboAlero has the HP Tuner for his 3400. From what I'm hearing through several others, it's not as user friendly as the DHP. Maybe it's just a question of familiarity.

[Frostbite545]

Ok thats what I thought. So getting the sim will just basically give the first sensor back the reading it wants, even though the O2 readings are different from what it wants them to be. Only thing is, shouldnt DHP have programmed the PCM to accept the different readings, seeing as how its tuned for "intake and exhaust" ?

[jackal2000]

Ok thats what I thought. So getting the sim will just basically give the first sensor back the reading it wants, even though the O2 readings are different from what it wants them to be. Only thing is, shouldnt DHP have programmed the PCM to accept the different readings, seeing as how its tuned for "intake and exhaust" ?

OMFG. the 2 o2 sensors DO NOT interact!!!!!111one

the sim will tell the PCM that everything is fine with the catalytic converter and to have a nice day.

[Frostbite545]

So the sensor just has to send the same signal to the PCM then. :lol: I can be a bit dense, and the mind numbing work at my job doesnt help... I think i got ya now.

[jackal2000]

great scott! i think he's got it! lol

[Spilner521]

Unless you changed the cat, adding a cat-back exhaust doesn't do anything to disrupt the after-cat O2 sensor. Get the code checked, it may just be a O2 heater circuit malfunction, which basically means the sensor is going bad. If that's the case, you should just be able to install a new sensor and the code will clear itself. If it gives you a cat inefficiency code, install a new cat. There's no need to mask the problem, get it checked and fix it, it may be nothing or may be causing you to lose power also.

[Frostbite545]

Unless you changed the cat, adding a cat-back exhaust doesn't do anything to disrupt the after-cat O2 sensor. Get the code checked, it may just be a O2 heater circuit malfunction, which basically means the sensor is going bad. If that's the case, you should just be able to install a new sensor and the code will clear itself. If it gives you a cat inefficiency code, install a new cat. There's no need to mask the problem, get it checked and fix it, it may be nothing or may be causing you to lose power also.

As far as I know, when the code was checked, there was nothing wrong with the sensor itself, it was just the difference in 02 readings throwing the code. Wouldn't the exhaust change the backpressure etc ? Thats what I asssumed was causing the problem

[Spilner521]

As far as I know, when the code was checked, there was nothing wrong with the sensor itself, it was just the difference in 02 readings throwing the code. Wouldn't the exhaust change the backpressure etc ? Thats what I asssumed was causing the problem
Reducing backpressure on the exhaust won't do anything but help performance, it definitely shouldn't throw an after-cat O2 sensor code. And since you didn't actually do anything to the cat itself, the reading the rear sensor gets should be the same as stock. Do you know the exact number of the code by any chance? It should show PO and a 3 digit number.

[Spilner521]

As far as I know, when the code was checked, there was nothing wrong with the sensor itself, it was just the difference in 02 readings throwing the code. Wouldn't the exhaust change the backpressure etc ? Thats what I asssumed was causing the problem
Reducing backpressure on the exhaust won't do anything but help performance, it definitely shouldn't throw an after-cat O2 sensor code. And since you didn't actually do anything to the cat itself, the reading the rear sensor gets
should be the same as stock. Do you know the exact number of the code by any chance? It should show PO and a 3 digit number.

[Frostbite545]

I dont have the scanner, my mech does, I would have to get him to scan it again for me...

[jackal2000]

good luck getting that sim

http://thechromepony.com/News-07-10-07.html

[Cliff8928]

Wow, I know that guy! The place is right down the street!

[Frostbite545]

Think this will work ? I may just replace the O2 simulator with a new one, I dont want my car to be running illegally if I can avoid it. Spliner, if i give you the code, do you think you can tell whats up ?

http://cgi.ebay.com/ebaymotors/Dual-O2-Oxygen-Sensor-Simulator-For-all-OBD-II-Vehicles_W0QQitemZ220130679985QQihZ012QQcategoryZ1 33195QQrdZ1QQssPageNameZWD6VQQcmdZViewItem