OK my front o2 sensor is toast. Does anyone know if the 1g o2 sensor will work on a 2g car?

Judging by the part numbers listed on Advance's website that's a big no.

Make sure if you're buying an O2 sensor to get a Denzo or OEM Mitsu sensor. The others that you find at other auto parts dealers are less than accurate for the turbo cars.

http://www.jnztuning.com/catalog/product_i...products_id=106

I have a good 2g o2 sensor for sale.

pm sent

Also can anyone explain upstream and downstream??

before and aft the cat.

Well i knew that but does anyone know what the diferent is between the sensors in how they read. I am assuming it is how the ecu reads it.

Ok. FYI I dont believe there is a diference between the front and rear o2 other than the harness.

The two sensors are both narrow band sensors. The second one is just a ecu check for the cat. You don't need to even have one other than to get rid of the CEL.