Replaced Knock Sensor in 96 Maxima

[PTG1212]

Last night my son replaced the knock sensor on his 96 Maxima. He used the typical set up described in a number of posts. 12mm socket connected to universal connected to maybe 9in or so of extension. First night he tried the socket would slip off when applying torque. Last night he decided to remove air intake parts (from throttle body back). Removing those parts, which isn't a big deal, gave him more of a straight line shot to the knock sensor. Once doing that he had knock sensor off in 15 mins or so. New one also went on in about 15 mins.

The improvement in performance is amazing. You read other peoples posts about it, but it's something else to experience it yourself. With the engine able to perform to spec after running in default mode for so long, it's like driving a new car.

He bought the Nissan knock sensor off ebay for $65 delivered.

How he found out the knock sensor was bad. His CEL lit due to a crack in purge valve. Went to Autozone to read codes and purge valve and knock sensor codes showed up. Replaced purge valve, CEL went out (after resetting) knock sensor code still there.

Anyway, thought I'd add some more input to the knock sensor knowledge base.

[Mrbizness1]

My daughters 96 Maxima had evap and knock sensor codes also. After changing the knock sensor I found no difference in drivability. Then I changed the purge valve and the CEL light went out. The shop told me that sometimes evap codes will also trigger a knock sensor code. On my 98 Altima last year I had the knock sensor code as well as the purge valve code. I changed the purge valve and cleared all the codes and the CEL light never came back on with the knock sensor code. Yesterday the CEL light came back on with the knock sensor code and a different evap code. I don't know what the evap system has to do with the knock sensor but there must be some kind of connection.

[PTG1212]

I agree, evap codes and knock sensor codes appear together a lot. Hard to tell, because the knock sensor wasn't turning on CEL. We suspect his knock sensor had been bad for some time. He had noticed a decrease in performance but did not know why. The crack in the purge valve caused a leak which did light the CEL. So when he went to Autozone, both codes were read. So, do they really appear together, or is knock sensor there but undetected due to not triggering CEL? In his case we believe knock sensor had been not functioning well before the purge valve issue, but went undetected because it didn't light the CEL.

When we examined the old knock sensor it had a crack around the body. The difference in performance with new knock sensor was significant. From everything I've read knock sensors eventually fail. Seems to be a fairly common problem on older Maximas. Have to say though, that 96 Maxima is a pretty nice car.

[sonicrunch]

You guys who felt no difference. Are you running premium fuel?

[aznstormin]

Originally Posted by PTG1212

So, do they really appear together, or is knock sensor there but undetected due to not triggering CEL?

Ah..knock sensor... very common problem. No, it does not trigger the CEL. It is a ghost code. Usually a different issue lights it up and the you'll find the KS code. And to solve it is usually replacing the ks.

[MASTERGUN]

Where is the knock sensor located on 1995 Nissan Maxima

[MASTERGUN]

Originally Posted by MASTERGUN

Where is the knock sensor located on 1995 Nissan Maxima

?????

[sonicrunch]

Originally Posted by MASTERGUN

?????

Under the lower intake manifold.

Check out Maxima.org for detailed instructions.

[98maxima06]

I have a 98 maxima 86k just got it. It drove great for about 800 miles then i notice something wrong with the acceleration above 30mph like the gears wernt changing right. I had a Knock sensor code but was told the knock sensor doesnt have much to do with the transmition could it be a different problem? Or should i spend the money on the knock sensor and everything will be fine.

[aznstormin]

Originally Posted by 98maxima06

I have a 98 maxima 86k just got it. It drove great for about 800 miles then i notice something wrong with the acceleration above 30mph like the gears wernt changing right. I had a Knock sensor code but was told the knock sensor doesnt have much to do with the transmition could it be a different problem? Or should i spend the money on the knock sensor and everything will be fine.

True knock sensor won't affect much with the transmission.

Please go into more detail with your acceleration problem.
Are you unable to go above 30 mph? Overdrive on/off? Engine light on? -If so, what are the other codes? [...]

[Nahkapohjola]

Originally Posted by 98maxima06

...the gears wernt changing right. I had a Knock sensor code ...

KS Knock Sensor is engine safety feature. You may tst bypass it before swap. See p9, link below. Faulty KS causes excess gas consumption, laziness as ign is retarded. Error code may or may not be true...

A/T has its own diagnostics, try testing. All starts from checking oil level, charge voltage at TCU = A/T ctrl computer. Seek more info via http://www.cardomain.com/ride/748507/15

[98maxima06]

The engine light is not on i can go above 30mph but it just doesnt fell right, like the gears aernt switching right. If i put the o/d off the rpms go really high. Sooner or later above 30mph it feels like it catches up once i establish my speed"60mph". The rpm gauge also seems to get stuck once in a while like it will pause. The way i get the rpms out of pause is hit the accerlartion and the rpm gauge will move agian. Another thing i noticed it only happened a couple times on cold starts. when i turn the car on the rpms go up a little like usual then it will drop right down to 0 and the engine will shut off. That is the only code that comes up. There was another person on here who had the same symptoms as me and replaced the knock sensor they said it was fine after. I want to believe that but dont want to fix the wrong thing Thanx for your assitance