on a 99 prelude we are installing an air/fuel autometer guage. do i wanna use the 1st O2 sensor? what color is the wire i need to hook up the signal wire too? thanks fellas.

 

You really want to splice into the ECU line and not the O2. Use the first O2 sensor and the signal wire should be the black and silver/white striped wire. Word of caution. If you have the Autometer AF and are looking to tune with it I highly do not recomend it. The meter is extremely inaccurate. The only thing the Autometer AF is good for is to look pretty.

 

i dont trust any guage that i can get for under 300 dollars. ill take a widband if they were less expensive... thansk man.

 

is there only 1 black and silver with a white stripe on the ECU?

 

For the most part your O2 sensor is made such that it will only tell U if your A/F is more than 14.7:1 or less than 14.7:1. If your A/F is just a little bit less than 14.7 the voltage from the sensor will drop to it's min value, and if your A/F is just a little bit over 14.7:1 it will shoot right up to max voltage. If U were to look at the voltage of the O2 sensor while your can is running in closed loop fule trim mode, U would see the voltage occilating from min to max about 4 times a sec. Your ECU is keeping the A/F right at about 14.7:1, it goes a weeee little over then a weeee little less, and back. Anyway your O2 sensor is not a good indication of the A/F but just if it is more or less than 14.7:1

If U want to read the A/F U need a wide band O2 sensor, but replacing the stock type O2 with a wide band would mess up what the ECU is trying to do (keep the A/F optimize). So what ya need is to install a wide band 02 sensor and take it's output to your A/F meter, and also take it's output to a little circuit that would take a reading of anything greater than 14.7:1 and max the voltage to the ECU, and with a readeing of anything less that 14.7:1 send the min value to the ECU. I have no idea if such a circuit exists on the market, but would be fun to build one.. it should work




[Modified by 57STS, 12:17 PM 10/9/2002]

 

The Black and silver wire is on the O2 sensor it's self. If you want to tap the ECU, I don't remeber which wire it was. I'd have to take a look at my Helms. It's either the green and silver or brownish/Orange and silver.....I think......

 

taping the o2 sensor is actually easier for me cause i have it sitting here. so i connect it to the silver and black wire? i dont have one that color