Jimothy12

iTrader: (2)

Is there a way to electricly test my knock sensor to see if it's bad? My gas mileage has dropped to around 21/22mpg with mixed driving. My check engine light is one but it has been for a while. I clear it and it comes back even when my milage was higher. It gives me knock senor and O2 sensor codes. The O2 code because I have a whole in my exhaulst.

So I'm looking for a way to test my knock sensor to determine if I should or should not replace it. 96 SE 198K miles

heynow

iTrader: (1)

Read the sticky's man, you've been here long enough! The o2 sensor might be bad with or without an exaust leak. That would definetly cause worse mileage.

Jimothy12

iTrader: (2)

I read the stickies first. I was looking for a way to test my Knock sensor, not the O2 sensor. Thanks for your reply though. Next time I'm under my car I'll test the O2 sensor as well.

Mxrider52

iTrader: (8)

Obviously didnt look hard enough. I mean you can even search so I dont see how you couldnt find this info.

The KS may be checked with an ohmmeter.

1) Raise the hood. View the engine from the driver's fender. Look into
the deep valley between the cylinder banks and below the intake manifold.
Identify the KS as a black item fastened to the block by a single vertical
bolt. A wire harness wrapped in black leads toward you, out of the valley.
That is the KS sub-harness.

2) Follow the KS sub-harness to it's nearest connector. This is connector F121.
It is located near the upper right-hand corner of the valve cover of the forward cylinder bank, as viewed from the front of the car.

3) Disconnect F121. You have to do a "press the latch and wiggle and
pull" to disconnect it. F121 has only two pins; if you see more than two
pins, you have the wrong connector. Use a digital ohmmeter capable of
measuring more than 10 Megohms. You want to measure the pins of F121, not
the sockets of the matching connector. Measure the resistance between a
good ground (such as the battery negative terminal) and pin #2 of connector
F121. On my car this is the highest of the two pins, the one closest to
the front of the car. The factory spec is 500 - 620 Kohms.

Double E

Screw the test. Replace the f'in KS. They're a known failure point. It's not fun, but worth the hassle. Fix the other stuff too.

Jimothy12

iTrader: (2)

Ha ha I hear ya. BUT I'm getting married in July and we have plans to buy a SUV sometime soon after. My max is starting to have problems and its becoming to hassel to keep fixing. It will be a sad day. This is my second max

heynow

iTrader: (1)

Wah,wah,wah!!! It's not like they're real problems. They're just sensors.

ShowGun

Do you test the knock sensor with the car on the on/acc position or with the car running. I tried testing with the car turned off and go nothing.

Turbobink

iTrader: (2)

you just pull the sensor and check for continuity. no continuity = bad sensor.

removal of the sensor is quite easy. you need to remove the air box top and air intake tube. you can then access the sensor with two to three rachet extensions, a swivel socket adapter and the appropriately sized socket.

Jamaha80

Ignition off
Remove KS with wiring harness still attached so you can fish it out when disconnected
Disconnect KS wiring harness
Check resistance between terminal 2 on KS and ground for 500-620kohm

DO NOT DROP THE KS!!!!!

Thats just to test the KS itself. If it's a wiring issue, there is a wiring harness from the ECM to a sub harness in the engine bay that connects to the KS. So, 2 wiring harness to check for continuity/correct voltage if the KS itself isn't the prob.

Although, when I had bad 02 sensors, I also recieved a KS code. A leak after the 02 sensors shouldn't trigger an 02 related fault code. I did'nt need to remove any other parts to get to it, and my hands are average size.
No, wait.. I had my wife pull it out with her smallish hands......

Not everyone can afford to think like that. They arent known to fail as much as the KS fault code is known to be triggerd by other problems.

tosheto

iTrader: (5)

I tested my KS and it shows 1200 Kohms and that is double of what I read is supposed to be. Should I just replace the damn thing. I get a P0325 code, but the check engine light is not on. Any help is appreciated!

internetautomar

iTrader: (30)

yes replace it so you can let it do its job

crash_landing

iTrader: (1)

i think it should be in the ball park of 500k on your meter. if its open, or 0 then replace it. You can just follow the wire the the connector and test it there. if you are gonna scrape your hands up getting it out then you might as well just replace it. check ebay. if you go to the dealer they may make u get the harness as well. depends on the area.

maximatech12

If you take a sowing needle and shove it carefully into the back side of the harness plug you should get 2.5V.
My aftermarket sensor only puts out 1.9V. Could this cause a hard start?
If the P0325 only flashes once then the ECM resets when a new one is put in?
If the new KS fails will I get a CELP0325?