P0325 Knock Sensor Code

2002 Toyota Tundra 4.7L V8 TRD

Check engine light is on and I have the code p0325. Went ahead and took everything apart to get the knock sensors. I replaced both knock sensors and had continuity between the sensors and the PCM. Put everything back together and I'm still getting the code.

Does anybody have any ideas? Kinda tired of the bad mpg(8-10 ). Thanks.

 

Are you sure it's not knocking? Not all engine vibrations are audible. Is the engine running smooth? Some bad gas? Worn plugs? Carbon build up creating a hot spot on the piston. Run some fuel conditioner through the engine.

Code doesn't mean that's the defective part. Could be the result of another problem.

 

Thanks for the reply.

The engine does seem to surge when it warms up. In fact the code doesn't show up unless the engine is warmed up. I already replaced all plugs and coil packs. I have tried fuel additive but it didn't seam to do much.

Should I try more fuel conditioner? I've heard it can clog your catalytic converters if used excessively.

 

Good fuel conditioners like 44K, Techron and Seafoam can actually help clean your converter and O2 sensors.

Have you cleaned your throttle body and MAF sensor? They can cause the symptoms you describe.

Sounds like you might also have a vacuum leak or a lean condition.

 

I replaced the MAF sensor last month and it didn't seem to do much.

I haven't tried cleaning the throttle body though, I might try to do that today.

There are some vacuum lines that look a little cracked, but I can't hear it sucking air from anywhere.

 

That throttle body cleaning is a huge engine performance enhancer if it is indeed in a fowled up state currently. Helps with idling at low RPM and low speed braking/steering.

Hows your PCV Valve looking? If nasty, replace with new. They are under $20. You’ll need the rubber grommet that it fits into as it may be dry rotted.

These are all cheap easy POSSIBLE solutions. Check all your hose connections as PCJ suggests. They are prone to coming loose.

 

I'd check for vacuum leak in the manifold to make sure everything is seated correctly. Use a propane torch(minus the flame) and wave the tip around the base of the manifold with the engine running. The RPMs will increase when the engine draws the propane gas into the engine through the source of the leak, if there is one... That could cause a misfire which the ECM could blame on the knock sensor

 

Had the same problem with my 2008 Toyota Tundra changed knock sensors and harness and still would trip when the engine warmed up. Cleaned the throttle body and it hasn’t came back on.

 

227k on the car. Toyota Sequoia, 2UZ-FE, same engine like in Tundra.

While driving about 45mph check engine came up, along with abs and stability control. Not sure why Toyota set this up this way, possibly to scare people.

Scanned it with regular scanner, displayed p0325, left bank knock sensor circuit malfunction.

After reading bunch of forums looked under manifold and found chipmunk nest. Everything was suggesting that wire or harness has been chewed up by rodents.

You have to take the intake manifold off, don't be scared it's not that bad of a job. You don't have to disconnect the fuel lines, just flip the intake manifold over on the right side, it's got flexible fuel lines, just be careful it's pretty heavy, get a stool or something to stand on.

I have tried to test bad sensor, you have to have oscillograph because all toyota knock sensors are piezoelectric resonant sensors, which means you can't test with voltmeter like old knock sensors.

Weird thing is that when you reset the code, started the car, let it run, revved up to 3000 rpm, no code.

But when you start driving it more than 1700 RPM, it's on again.

Dealer wanted 1000$ + to replace both sensors.

Anyway, purchase 2 brand new TOYOTA OEM sensors, 209$ at local dealer. I have purchased 2 of them for 250 including shipping from Toyota dealer online. Look for deals and free shipping coupons. Here at McGeorge Toyota Online Parts check around may be some other places have it cheaper, but this one was the cheapest for me because they had free shipping coupon.

DO NOT BUY AFTERMARKET SENSORS if you don't want to redo this job again)

Wire harness ended up being in good shape, rodents didn't damage it.

Be careful, don't break stupid knock sensor connector tab. If you do like I did, use small zip ties to tie it down to the sensor or silicon around.

I have purchased new intake gaskets online, from the dealer, 30$ each. If you are on the budget, just clean them up and reinstall.

Make sure when you install manifold gaskets, they go the right way. Many videos show them installed wrong way.

There are 2 small rivets on each gasket, the round head of the rivets should facing motor. If you have 2 rivets round heads facing up, somebody already been there, and installed gaskets upside down)) on new gaskets, one metal tab marked with white, make sure its facing down to the motor.

Anyway, no code whole job cost me around 300$ with 2 brand new OEM toyota sensors and OEM gaskets.

Good luck guys and happy wrenching)))

 

I can't find any info on that engine. 1st Gen Tundra and Sequoia only came with the following engines:

• V8 4.8L (2UZ-FE) -- 2000-2006
• V6 3.4L (5VZ-FE) -- 2000-2004
• V6 4.0L (1GR-FE) -- 2005-2006

Sequoia is +1 year of manufacture, but numbers should match up.

Did you mean 2UZ-FE vs. 2FE-ZE?

 

LOL yea 2UZ-FE, 4.7

 

I usually don't hang out in chats but this is my first Toyota Sequoia ever. I've had about 30 cars for my personal use in the period of 27 years))
Try to do intake manifold or tune up 1997-2002 Ford Expedition)) some mechanics can't get to the back passenger side spark plug, so they don't replace it)) charging you 800$ for a tuneup))

 

I have corrected my original post with correct engine 2UZ-FE.

 

Just one more thing, while I was doing this job, I have cleaned original PCV valve, just used some carburetor cleaner and air. Came out nice. Also replaced few vacuum hoses because they had some small cracks on the ends, they were not bad, just replaced them, it's a cheap insurance.

Engine was not nocking, and didn't have any vacuum leaks or any other codes for lean condition or anything like that. So, if you have a problem after installing Aftermarket sensors, it's probably the Aftermarket sensors causing this again.

The way they do the diagnostic tests for knock sensor issue, they create lean condition so engine start pinging/knocking and measure the signal to the ECU. If there is no signal, sensor or wiring harness is bad. Correct me if I am wrong.
I never took it to the dealer to do the diagnostic test

Part numbers for new sensors and pics of the good old OEM sensor