i have that same problem-- i see that whenever its throwing that particular CEL-- the car runs louder and does not sound as well. It also lags a bit when it comes to acceleration and is unable to get all the way up in the RPMs... Also, I am 110% sure its dumping WAY too much fuel-- at least for me, the carbon buildup in my exhaust is BLACK. I am looking for a wsolution-- only thing i can come up with so far is just to buy an OBD-2 for my laptop and just reset the CEL every time it comes up-- plus I can use the laptop to control the ECU a bit.

 

The 2nd O2 sensor is made to assure the normal function of the cathalyser.
I'll never know if it has been done to avoid "us" to put high flow cats, or just to check the work of it.

The oxigen sensor measures the O2 in the exhaust gases, so they're different before the cathalyzer than after!
The problem is that it isn't just a resistor, it is a device that generates electricity 0.1 Volts! It needs to be hot to work, and it oscilates depending on the exaust gases O2 content. The ECU tunes the mixture depending on this values.
Some cars will go into limp mode, but it depens on the maker of the ECU. Maybe our tibbys doesn't have this feature (Thanx to heaven!), and it wont affect your mileage.
I've just seen some OBDII trickers to make think the ECU it is all OK, on the internet, but they're for GM cars or trucks!

 

Guess we just didnt get lucky-- some people just got the right Tiburons... oh well.

BTW DO NOT try the resistors on the Tiburon, they absolutely do not work. In fact, I had one and it threw a CEL that could not be turned off with 2nd o2 sensor having too much voltage.

 

I just got some headers and flex pipe. It only came with an o2 on the flex pipe. So i was wondering should i get an o2 bung put into the header or just not worry about it? Then should i bolt it up with out a cat or cut part of the mid-pipe and have a cat put in between the header and the flex pipe

 

Ugh, simple $25 fix:

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...sspagename=WDVW


Worked for me and no more CEL. YAY!
laugh.gif

 

when i put my headers in it only came with one bong in the down pipe, so i made an other one after i relocated the hi-flow cat witch i put under the car. the second 02 is after the cat so i had to extend the second 02 wire and i have had no problems with this set up. you need one 02 before the cat and after the cat or your check engine light will come on. the 02 sensors tell each other what to do after they read the before and after. i passed e-test no prob. try this out

 

Every car manufactured with OBD-II has two o2 sensors (unless duel exhaust). Every car manufactured after January 12, 1996 has OBD-II. Every car in that time either enters limp mode all the time when a CEL comes on, or it enters limp mode all the time except during full throttle. Thats the requirement by law. Cars manufactured 2004 [or 2003, can't remember dates exact] and on enter limp mode all the time.

So, if you have a Tib, you have OBD-II. Hyundai I believe started doing it a few months before the final date. So all Tibbies have it.

 

Some tibbys doesn't have OBDII system!
Mine was bought in July 1996, and the serial number is about 3700 from Ulsan factory!
Mine is MAP based, and has only one O2 sensor.
I've supressed the cat, and never had a CEL light. I think I also doesn't have the bulb!!!

You can see here the Supressor (From IRESA, Spain), just behind the radiator fan.

This is the rest of the exhaust pipe, tha thing is a flex pipe, non a second cat! We also call it "Flame killer", but doesn't work as a cat. Of course, there is not second O2 sensor.

Sorry about the mud, it was a rainy October!!! :-)

 

I figured there could be some since the requirements started January 12, 1996. Yours must've been one of the first Tibbies built ever. laugh.gif