If I'm unable to read the odb2 on my 97 maxima
 

I assume the the connector is broken because my odb2 says no connection. The DMV could not connect either and they had to use the tailpipe for the emissions testing. I passed emissions just fine. However I still had a cel on my odometer until I replaced the odometer (now the light is out. Most likely the light bulb is out)

Any ideas what computer component should be replaced?

I would check the wiring on the OBD connector before you buy anything.

Check for a fuse next; look in the owners manual, on the fuse box cover, or on-line to ID the correct fuse. Might be Fuse #40 - 7.5 amps.

does the light turn on when you open the switch...? and do that try the fuses first...cuz the way i get my codes is thre the niss-2 connector i dont use the obd 2....

I use OBDII scanner on my 97 w no problem. Was working on Ford Expedition a while ago where OBDII was dead due to a fuse.

If you get no power from the connector then check the fuse, but if you get no data from the ecu then check the wire running to it. When I went for emissions, mine would not read because there was no data being transferred due to a short in the data wire. I ran a new wire from the ecu to the obd2 port and problem solved; our cars are old this stuff will happen.

Thanks guys for the help. It was the fuse and now the clock works too.

It looks like the standard codes P0446, P0440, P0325, knock1 circuit1 bank1

The knock sensor code will not turn on the CEL. In PA it will not even fail emissions with that code. I would look into WA's requirements. It may not be worth replacing.

Surprised that you passed WA emissions with check engine light, frankly. Unless the light was out (bulb) when you went, and the obd2 was also out @ same time... usually the DMV won't even pass you with CEL on...sounds like you may have gotten lucky :)

The KS will not trip the light by itself...but the O2 codes you mentioned will.

what is the niss 2?? Where would i find it because i am not able to read through my obd 2, my number 40 fuse keeps popping and i have no idea why!! My check engine light is on but cant read any of the codes.

:buttkick:
It is worth replacing.