I have recently noticed that I have been getting horrible fuel mileage and it is really bothering me. So I figured something was up. I tried to see if any sensor was acting up or if my ECU would say anything, and what do you know, I pulled a knock sensor code. Damn. Is this the reason why I have been getting bad fuel mileage?

BTW, where is the cheapest place to get a new knock sensor? Thanks guy.....

 

Knock retard due to a bad knock sensor will most definitely reduce your gas mileage, as the engine is not burning fuel as efficiently as it should. You end up having to step on the gas more to get the car to move the same, causing increased gas usage.

I just bought a new OEM knock sensor from Courtesy Nissan for $140 shipped. (~$135 + $5 shipping). This is about as cheap as you're going to find. Tell them you're a maxima.org member and they'll give you the discount. Number is 972-644-3942.

 

Your knock sensor may not be the problem. The sensor is actually a passive sensor. It generates no voltage until it senses knock. Then it generates a voltage....telling the PCM to retard spark. So you might wanna find out why its generating a voltage first. The sensor COULD be bad. Try other things first, like finding out what your fuel pressure is, how long has it been since the fuel filter was replaced, making sure nothing is blocking your intake, oil level, and other basics.

 

Well, I already know my fp because I have the full sweep gauge for my nitrous setup. That is all normal. I replaced the fuel filter about 7,000 miles ago, so I am ok there too. I am gonna replace the knock sensor anyways since I do have 150k lol. So I will keep you all posted.....

 

Try tustin nissan in the group deals section. I got my cam sensor from them for about 30 dollars less than list. Hope this helps.

 

erik you are pretty inclined, mechanically but if you need a hand holla. i changed mine a few months ago and it made a world of diff. change it out and your deep in the 13s.

 

then to the dyno young one?

 

I would also check the engine grounds. You would be amazed what a brand ground wire will do to the complicated electronics.

 

don't go out and buy a knock sensor.. ..

the knock sensor code is usually followed by another code a week later.. so reset the ecu and wait for it to come back..

chances are your o2 sensor is fried.. and its kicking off hte knock sensor code.. i have seen people waste $180 on a new knock sensor when it was not needed.. it was the 02 all along..

so just reset and wait till it comes back..

FYI: i was getting 12 mpg past month.. last weekend i did .. fuel filter, plugs and oil and i am getting 27 mpg .. so check those also..

 

Well, also think of this, I have 150k. I will check the O2 sensors, but I have already reset my ECU one time before but the knock sensor code came right back that same day. I am gonna replace it anyways. I am gonna look into those O2 Sensors though. Are they the ones in the y-pipe? Thanks guys.

 

Yes sir they are. BTW I get about 15 MPG on avg in town.

 

Because you floor it every time off the line to hear your intake...........

 

And that is a bad thing????