High Nox

[89Foxbody]

Hey I recently failed smog I have a 65mm throttle body, JBA headers, X-pipes, and 3.55 gears. I also have an aftermarket water temp and oil pressure guage. Here is what i got.

@15mph

%CO2: 9.5
%02 : 7.1

HC: 40
(MAX 121 AVE 31)

CO: 0
(MAX .76 AVE .10)

Nox: 1104
(Max 807 Ave 237)


@25mph

%CO2: 9.0
%02 : 7.7

HC: 26
(MAX 96 AVE 20)

CO: 0
(MAX .65 AVE .09)

Nox: 954
(Max 746 Ave 199)

Now, would my aftermarket temp gauge make the computer think the engine is always cold, thus advancing the timing and causing more nox, since my stock sensor is not connected? Or does the computer recieve engine temp from another source?

If thats not it, what could be causing my high nox and almost NO CO. Could it be a lean mixture, or possible intake leak?

Thanks.

[dogbreath077]

Connect up the stock sensor, and then retest. I'm surprised they ran the test with it disconnected.