wasup fellas, when will I know that I need a new Knock sensor and O2 sensor? Is there any symptons that can pin point exaclty this is what I need?!
Also, as for the O2 sensor, I ve heard that there is more than 1, is this true and if so where are they located other than the "y"... Thanks

where can I get these sensors for a "resonable" price?

jae

 

our cars only have 1 o2 and it's supposed to be replaced every 60-100k lots of people (myself included) let it go for longer, but the price paid is decreased fuel economy.
and you shouldn't need a knock sensor on yours cause it's a VG.

http://internetautomart.com/maxima/3rdgen/tuneup.html third column

 

Internetautomart, okay thanks for the advice, however you mention that the VG's dont use a knock senor but on your site you offer a knock sensor for the VG 90-94 just my thoughts...

Jae

 

no I said "and you shouldn't need a knock sensor on yours cause it's a VG." they rarely go bad on the VG, but it still uses one

 

I know I should know this by now, but how exactly does the knock sensor work and how can you tell when it's bad. Internetautomart, you're probably right about not needing to replace but I have almost 200K so I am just curious

 

the knock sensor is essentially a microphone to pickup unusual noise in the engine which it will assume to be detonation (detonation=bad) it then will cause the computer to retard the timing which causes the engine power to decline and use more fuel.

 

okay could a bad knock sensor cause your car not to start?

 

No. The piezo element detects [if any] ping, sends minuscle signal to ECU, ECU retards ignition timing.

Ping might come for exampl from too low octane gas, excess soot causing pre ign in engine. Seldom needed, but maximizes engine life with unaware drivers...

Copy from somewhere:
The knock sensor on VG30E engines is located under the rear exhaust manifold.
Just use an ohm meter at the subharness and check each terminal (going to the KS) to ground (battery negative). Resistance should be around 0.5 Meg Ohms (500,000 Ohms). When mine was bad it read 5 Meg Ohms (5,000,000)

Can be fooled with a resistor (they say).

 

Well I guess thats not my problem my car won't start period

 

- does the starter work
- engine crank
- spark present
- injectors click
- gas available
.
..
...
- ECU give any codes?