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A little help please.. Knock Sensor/O2/ + Codes

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Old 04-23-2009, 10:26 AM
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A little help please.. Knock Sensor/O2/ + Codes

Hey my check engine light came on, I bought a dtc, read the codes. Bad Knock sensor, b2 s1 O2 sensor, Incorrect Gear 2 & 3 ratio, Eng

P0150 B2, S1
P0325 Knock Sensor Bank 1
P0725 Engine Speed Input (wtf is this?)
P0732 Gear 2 Incorrect Ratio
P0733 Gear 3 Inc. Ratio

So, Im going to buy an O2 sensor and a knock also. But I need to know a couple things first.

The B2, S1 Oxygen sensor would be which one??

http://www.partsgeek.com/catalog/199...en_sensor.html

There is one for Left Upper and another for Right Upper.. Does it matter which one I buy? They both appear to have the same part number.. B2,S1 just means the location and not the specific part right??



What does Code #P0725 Engine Speed Input.. Mean?? My Idle speed is correct btw.


And one last thing, how do I solve the Incorrect Gear ratios? I just had a full transmission service about 2 months ago..
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Old 04-23-2009, 10:33 AM
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B2S1 is the upstream on the left/front bank.

Yes, it just means the location. If they're the same part number, it doesn't matter, but it's the 'left upper' sensor.

P0725 is a TCM/ECU communication issue. A bad TCM could also cause your issues with the other trans codes, as could a damaged or corroded harness, or a connector that's loose.

Don't bother buying the KS until you've fixed the other codes, you probably don't even need it (especially with an O2 code present).
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Old 04-23-2009, 10:38 AM
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Originally Posted by pmohr
B2S1 is the upstream on the left/front bank.

Yes, it just means the location. If they're the same part number, it doesn't matter, but it's the 'left upper' sensor.

P0725 is a TCM/ECU communication issue. A bad TCM could also cause your issues with the other trans codes, as could a damaged or corroded harness, or a connector that's loose.

Don't bother buying the KS until you've fixed the other codes, you probably don't even need it (especially with an O2 code present).
Really don't get a knock sensor? I thought that was one of the main problems that I needed to fix..? My car stalls and turns off randomly and I thought the knock sensor might have something to do with that..
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Old 04-23-2009, 10:41 AM
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Originally Posted by SPER
Really don't get a knock sensor? I thought that was one of the main problems that I needed to fix..? My car stalls and turns off randomly and I thought the knock sensor might have something to do with that..
knock sensor will only give you a bit of power loss and crappy gas milage. Nothing to do with stalling or turning your engine off. Though I would get that looked into...lol..try cleaning your TB and IACV
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Old 04-23-2009, 10:53 AM
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Originally Posted by SPER
Really don't get a knock sensor? I thought that was one of the main problems that I needed to fix..? My car stalls and turns off randomly and I thought the knock sensor might have something to do with that..
No.
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Old 04-23-2009, 11:05 AM
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Originally Posted by Bassbreaker
knock sensor will only give you a bit of power loss and crappy gas milage. Nothing to do with stalling or turning your engine off. Though I would get that looked into...lol..try cleaning your TB and IACV
Ohh.. I knew it had something to do with emissions, but I wasn't aware that it didn't serve another purpose. So do you think it can come from the O2 sensor? Btw what is a TB? And when you mean clean the valve. How just wipe it down? How will that help?

I've got to go to work soon, but ill check back tonight..
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Old 04-23-2009, 11:10 AM
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Originally Posted by SPER
Ohh.. I knew it had something to do with emissions, but I wasn't aware that it didn't serve another purpose. So do you think it can come from the O2 sensor? Btw what is a TB? And when you mean clean the valve. How just wipe it down? How will that help?

I've got to go to work soon, but ill check back tonight..
O2 sensors are very unlikely to cause that as well.

TB == Throttle Body.

Basically, yes. Spray it down, wipe all the crap off.
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Old 04-24-2009, 04:53 AM
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Well I ordered the knock sensor and the oxygen sensor as well. Even though they aren't the source of the problem, Im sure it wont hurt to replace them..

Anyone have a clue what

P0725 Engine Speed Input means?

I've searched google and read some posts about people with the same code and they had the same problems as me. They're cars would randomly stall and shut down while driving. Some people said its the engine "speed sensor".

Last edited by SPER; 04-24-2009 at 05:57 AM.
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Old 04-24-2009, 06:01 AM
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I found a speed sensor for $30 online and ordered a fuel filter as well. Along with the knock and oxygen sensors. Im going to see if I can replace my radiator today. I hope its not too hard.. I'll get to cleaning the IACV and TB as well while im replacing it. Because everytime I drive my radiator sprays coolant all over the engine and all over the components. I never noticed that the leak spray UPWARDS onto everything until just a few days ago. And I've had this problem for months. So Im sure all that build up of coolant on everything probably isnt a good thing..
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Old 04-24-2009, 06:07 AM
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Originally Posted by SPER
Well I ordered the knock sensor and the oxygen sensor as well. Even though they aren't the source of the problem, Im sure it wont hurt to replace them..

Anyone have a clue what

P0725 Engine Speed Input means?

I've searched google and read some posts about people with the same code and they had the same problems as me. They're cars would randomly stall and shut down while driving. Some people said its the engine "speed sensor".
Again:
Originally Posted by pmohr
P0725 is a TCM/ECU communication issue. A bad TCM could also cause your issues with the other trans codes, as could a damaged or corroded harness, or a connector that's loose.

There is no 'speed sensor' for it, it's the engine speed signal; RPM, not vehicle speed.

The ECU sends the RPM directly to the TCM. Do the diagnosis per the FSM, starting AT-68.

FWIW if you paid more than ~$60 shipped for the KS, you paid way too much.

Originally Posted by SPER
I found a speed sensor for $30 online and ordered a fuel filter as well. Along with the knock and oxygen sensors. Im going to see if I can replace my radiator today. I hope its not too hard.. I'll get to cleaning the IACV and TB as well while im replacing it. Because everytime I drive my radiator sprays coolant all over the engine and all over the components. I never noticed that the leak spray UPWARDS onto everything until just a few days ago. And I've had this problem for months. So Im sure all that build up of coolant on everything probably isnt a good thing..
The only speed sensor we have is the VSS. If you ordered that, you're just wasting your money, honestly.

Radiator is a piece of cake, a couple wiring harness connections and a pair of bolts to lift the fans out, then the two hoses (and two trans cooler lines if you're an auto), then the two nuts on top and it lifts right out.
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Old 04-25-2009, 07:20 AM
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Yay! dartboard diagnostics.

Honestly man, throwing parts at your car that is doesn't need is a waste of money - if it ain't broke, don't fix it.
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