PLS Help with Check Engine light diagnosis!

[lagvoid]

After doing lots of searching I did come across the self diagnosis test for the check engine light. After doing the test, I can't break them down to figure our what I need to replace/repair. I've tried searching for codes but had no luck. Please assist me in any way that you can.

1995 240sx se (non california)Error code 133 - E exhaust gas O2 sensor circuit3 long beeps and 3 short beeps*I assume that the O2 sensor simply needs to be replaced

Error code 234 - Detonation sensor circuit3 long beeps and 4 short beeps*Is my engine detonating? or did something else fail?

Error code 3Not sure what the code means...I read 10 long beeps and 3 short beeps, this doesn't seem right? Anyone know what that error code is?

I took short video clips of the error codes if it helps.Error code 1 Error code 2 Error code 3

If you know what needs to be replaced/repaired, please instruct me on how to go about it the best way.Thanks for your help

[lagvoid]

Bump-Can someone please help?

[C-Kwik]

http://www.ecutecparts.com/ccodes/nissan.html

The 3rd code is 103.

Make no assumptions. The codes could indicate a problem with the motor where the sensor is triggered indicating something is wrong with the motor, or that the sensor itself has failed. It could even be a part that works with the part that was triggered that is causing the error code.

[lagvoid]

Thanks for the reply c-kwik, do you have any suggestions on how to go about this? Should I take it to the dealer, a shop, or replace parts?