i have an 2003 Audi A4 1.8t and i was just wonder which 02 sensor to hook up to my A/F gauge? and which wire color to connect to?

 

The front sensor is the wideband O2 sensor used to control the engine, the rear one is for the gas coming out after the cat.

 

ok... so ur saying the front one is the one i should use. so wat wire color should i connect to?

 

any other advice more specific????

 

You can NOT tap onto a wide band 02 sensor for a gauge. A wide band gauge needs its own dedicated 02 sensor which is why they come with one.

I sure hope your not trying to connect a narrow band AFR gauge to your wide band 02 sensor.

 

yeah i got a narrow A/F guage for now!! so is there anyway to make this work?

 

No it wont because that gauge works on 0-1 volts while the wide band signal is 0-5 volts.

You need to sell that gauge and start looking at wide band kits. Innovate makes some really nice ones.