2subaru4u

I Have A 2002 Wrx. Ive Been Trying To Install An Air/fuel Ratio Gauge But I Cant Get It To Read. Ive Hooked It Up 2 Both 02 Sensors But Nothing. The Guage Has Been Tested And Works Fine. What Am I Doing Wrong? Does It Need To Be Hooked Up Somewhere Else? I Would Appreciate Some Help. Thanks.

YOU CAN ALSO PM ME IF YOU HAVE ADVICE.

unstble

silly question...but do you have power to the gauge?

Mulder

Presumably you have the Autometer or a similar tap-in type A/F gauge. Unfortunately those are all but useless for any kind of real A/F readings especially in the turbo cars. They only work with a narrowband 02 sensor, which means you have to tap the rear 02 which is post-cat and also too far back in the exhaust stream so it won't give meaningful readings.
The front 02 is a special semi-wideband type and must NOT be tapped. Not only will the gauge not work with it, but tapping it will prevent the sensor from working correctly and cause the car to not run properly. Doing this can also damage the sensor or its wiring and require its replacement, and the cost of the front 02 is about $200.
If you want truly accurate A/F readings the only way to get them is with a wideband unit which includes its own dedicated sensor mounted in the exhaust manifold. Of course these are a lot more expensive than the cheap tap-in gauges. Also, if your car is stock or only lightly modded you do not need an A/F gauge, the need to monitor A/F only arises once the car has been significantly modded or tuned.

2subaru4u

thanks for the replies. the gauge does have power going to it. the car seems to be somewhat heavily modded and since i installed a fuel management system i just wanted to get a reading on the air/fuel ratio.

Mulder

Ok, then you may have a legit need for an A/F gauge. However this one will be of little use for the reasons I stated. If you are serious about monitoring A/F, consider investing in a real wideband.