I just installed my headers and I will be getting the GT cam soon. I have redone my exhaust, 2 1/4" mandrell bent piping and all that remains from my stock exhaust is the second cat, which I don't think I will be removing, yet. I completly removed the first 02 sensor and just have the second one installed. I will be relocating both sensors soon. My engine light has not gone off as yet, but I am being told that it will, eventually. Now, my question is, like i said I am planning on installing the GT cam and I was wondering if my engine light will go off then?

 

Almost forgot . Also, to add to what I had written. Will there be a need for an air/fuel regulator after the cam install?

 

The first o2 sesnor is the important one. The second sensor is just there to ensure emission compliancy. It merely checks to see if the 3-way cat ahead of it is functioning properly. That said, the 2nd cat on the 2000-2001 Tiburons is a 2-way cat, and in order to get the CEL to go off, you need to install an aftermarket 3-way cat (hi-Flow) after the headers, and mount the first 02 sensor before the Hi-Flow cat. The 2nd Cat (2-way) can be removed. That done, the second 02 sensor must be installed somewhere after the 3-way hi-flow cat.

The only way your CEL is going to go off is if:

a) Both o2 sensors are plugged in and working
cool.gif There is a voltage difference in the sinusodal pattern read by both o2 sensors at engine idle. (In otherwords your 3-way cat is working)

When the ECU sees this, it will presume the cat is doing its job, and your CEL will go off.

As long as the ECU thinks your are not emmissions compliant or if any sensors are disconnected you will get a CEL.

Also, your first o2 is used to determine if your running rich or lean. With it is disconnected, the computer will go into limp mode and over inject fuel, resulting in loss of power. With just the 2nd o2 disconnected, the engine will run the same, but you will get a CEL due to emissions failure.

Hope this helps,

-Steve

P.S. The GT Cam will not give a CEL when installed properly. It also moves Pk torque from 4850 RPM to 5350 RPM and peak HP from 6000 RPM to 6350 RPM. I saw a 5 WHP gain with mine. Its a worthwhile mod.

[ August 19, 2002, 08:23 PM: Message edited by: BV1 ]

 

Thanks for the info. I will be relocating my o2 sensors, but I guess my major concern was with the addition of the cam and the need of an AFC. Eventually I will op for a high flow cat.

 

BV1 is correct, the only way for you to get the CEL off is to put both 02 sensors back in your exhaust and add a high-flow cat.

The addition of the GT/XD cam doesn't require you to have a s-afc/afc. Your ecu can compensate for this since its very close to stock. Only when your into heavy aftermark cams or other high-lift/duration cams do you require the tunning of a s-afc/afc. But if you have your whole I/C/H/E setup then you can get a apexi s-afc and tune it a little better and get a few more horsies.

anyway

 

Wait a minute, I guess I need to explain myself a little better. When I said "gone off" I meant that it has not come "on". It has not come on as yet, even with the mods that I have done. But i understand what you guys are saying. I was just a bit curious since I only have that one O2 sensor installed that it hadn't come on and i'm not complaining .

 

woa, your not getting ANY CEL?

then something is definetly snafu. Your first o2 sensor find out if your car is running rich or lean. and if it doesn't get up to temperature your car is going to run on the default fuel map which makes it run rich.

anyway, really odd.

 

Did you just disconnect the 02 sensor, as in two days ago?
If that's the case, the 02 sensor may still come on. It can depend on how much you've driven the car since the work was done.
If you can get access to a OBDII code scanner, hook it up to your car and see if there are any codes stored in the ECU. Generally, the ECU might detect a fault somewhere in the OBD system, but will test the circuit a few times to make sure there actually is a fault and it's not just a fluke.
So if you give it a few more days, it might come on yet.
I too would be very confused if it never came on.

 

LOL!!!! See.... I totally disconected the first one from the harness and I just have the second one hooked up. So I guess it has nothing to do with still having the second stock cat. I installed it last friday, so i've been running with them for a couple of days now. we'll see what happens after I install the cam. hopefully i'll get it before my dyno date. I'll post some numbers. should be by the end of the month.