Car is running way too rich.....need help

[gst19psi]

i got a friend with a 95 gst and he is having some trouble and im stumped. He keeps running way to rich at first I thought it was a boost leak, but we changed every coupler/reducer on the car and still nothing; the strange part is the car still makes a hissing sound like if there is a boost leak. I tried raising the boost just a little bit to compensate but still same affect and now the cars boggs down, so I went back to stock boost levels. I'm beginning to think its a computer problem the car is running way to rich its crazy. The turbo is brand new and the plugs are brand new. So any help or suggestions would be greatly appreciated.

 

[silver bullit]

Boost leak test, o2 sensor, you can pull the computer to make sure the caps are not leaking, though search cause this has been answered so many times.

 

[JayRolla]

How do you know its running rich? What mods does he have. Could be thousands of different things, we need car info.

 

[Auto RS T]

A hissing noise is usually associated with a vacuum leak. Are all the hoses connected to the intake?

Besides just replacing couplers have you actually done a boost leak test to pinpoint the leak? Spray soapy water around the area if you can't tell exactly where it is coming from.

What other recent work was performed?

Check your rubber lines for tears and make sure everything is connected.

 

[scottsee]

pressure test...