Ok..I took my car to do a smog test and the guy said that my OBD II Port isn't working and the computer can't read it because I installed an aftermarket cd player. My mechanic is charging me to unplug it. I was wondering how can I reconnect the port myself? You guys have any ideas? I already search this up...

 

all you need to do is make sure the cd player is turned off and remove the face plate just to be sure it is off before they plug in the obdII port

 

aftermarket stereos can interrupt the k-line system the car uses to communicate to its sensors and the service connector. sometimes turning the unit off before you try works. but sometimes you need to remove the whole stereo and unplug it from the car.

 

Did you do the stereo install yourself? or have Best Buy or Circuit City or someone do it?
From what I understand-and correct me if i'm wrong, if the installation is done correctly (as in using the correct adapters, not just cutting and splicing wires), the K-line shouldn't be effected.

 

the K-line is affected with any aftermarket radio install in our cars since the aftermarket radio is not able to speak to the obd port when the audi radio is able to.

if i rember correctly it has something to do with the amp turn on wire from the aftermarket deck which is the blue/white wire. if this wire is hooked up it causes problems by feeding 12 volts to the obd port but with out this wire hooked up you will not have any sound from the rear speakers or no radio recption on the a4's that do not have a factory amp that powers the rear speakers.

if turning it off and removing the face plate doesn't work you can always pull the fuse in the fuse box on the driver's side of the dash, instead of pulling out the radio, but i don't know how much the inspector's computer reads our cars.