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2005 H2 Knock sensor nightmare. Please help!

  #11  
Old 12-14-2018, 08:26 AM
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Have you watched the fuel pressure while driving? Take out the two upstream 02 sensors and test drive it to see if the open sensor holes will restore your lost power.. If so ,your catalytic converters might be plugged.
 
  #12  
Old 12-14-2018, 08:54 AM
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Pull one of the pre cat 02 sensors and install a pressure gauge, pressure should be 1.5 psi or lower at 2000 rpm. The lower the better

Neal
 
  #13  
Old 12-20-2018, 12:02 AM
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Thanks again guys! I have done everything as per your advice and still the same.

The only thing I have noticed is that my H2 seems to dramatically improve every time I unplug the - battery. As a matter of fact, both times I have previously replaced the KS, the H2 drove great at first. Coincidence??

Any idea why unplugging the battery helps my KS nightmare??

I left it disconnected for a few hours this afternoon and then drove it for just a few miles. Great throttle response and power but, as it has happened before, I’m pretty sure it won’t last very long.

I will try to get it diagnosed with a tech2 because my obd scanner seems to not cut it.



 
  #14  
Old 12-20-2018, 10:01 AM
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When you disconnect the battery for a bit all of the learned long term fuel trims as well as a few other things get reset in the ECU tune....
 
  #15  
Old 12-20-2018, 11:21 AM
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Originally Posted by MixManSC View Post
When you disconnect the battery for a bit all of the learned long term fuel trims as well as a few other things get reset in the ECU tune....
Exactly! So the long term parameters learned by the ECU are messing things up. Hence it might be indeed a tune issue? I guess the current tune, that the ecu is reading after each “reset”, is what is causing all the performance issues. Or... the the tune is in ECU itself?

 
  #16  
Old 12-20-2018, 01:07 PM
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The tune is in the ecu itself. I doubt the tune itself is the problem but I guess that is possible if someone put a custom tune on it at some point that was adjusted for some performance accessory that is no longer installed. I think more likely is some sensors data is not reaching the ecu or it is giving a way out of range value and the ecu is overcompensating for it. Probably need to get a Tech 2 connected and start looking at sensor values to make sure the various sensors are all within spec on the range they are reporting. A bunch of them on the vehicle like MAF, IAT, TPS, CPS (cam and crank position). Just one of those tough ones to diagnose.... could even be a ground for one of the sensors is poor, voltage issues, fuel pressure, intake leak, etc.
 
  #17  
Old 01-23-2019, 07:09 PM
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Today, I decided to get dirty and removed the vapor canister and vent solenoid (a couple of days ago I got an error 0446 (Evap performance).

Opened up the vent module and this is what I found:



The filter was completely gone.... I replaced it with a new one.

I have also ordered a new charcoal canister that I should be getting in about a week.

Surprisingly, my H2 seems to have drástically improved!! Quite a lot more power and very little hesitation.

Can I assume that once I replace the charcoal canister this absurd nightmare could be over?

















 
  #18  
Old 01-23-2019, 07:54 PM
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Have you had any issues with filling the gas tank, taking a long time to fill (having to fill very slow)?

If you shake the canister you should be able to here the carbon moving around if not then its more than likely plugged

Unless the purge solenoid is stuck open the canister usually wont cause driving issues.

Neal
 
  #19  
Old 01-23-2019, 08:04 PM
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Originally Posted by legerwn View Post
Have you had any issues with filling the gas tank, taking a long time to fill (having to fill very slow)?

If you shake the canister you should be able to here the carbon moving around if not then its more than likely plugged

Unless the purge solenoid is stuck open the canister usually wont cause driving issues.

Neal
Thank you Neal,

yes, I’ve had a lot of issues filling up at the gas station, I had to do it very slowly...

Shaking the canister I could hear the pellets moving around. I suppose then that I rushed into buying a new one... :-(
 
  #20  
Old 03-13-2019, 11:09 PM
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Originally Posted by Hbrezzi View Post
Thanks again guys! I have done everything as per your advice and still the same.

The only thing I have noticed is that my H2 seems to dramatically improve every time I unplug the - battery. As a matter of fact, both times I have previously replaced the KS, the H2 drove great at first. Coincidence??

Any idea why unplugging the battery helps my KS nightmare??

I left it disconnected for a few hours this afternoon and then drove it for just a few miles. Great throttle response and power but, as it has happened before, I’m pretty sure it won’t last very long.

I will try to get it diagnosed with a tech2 because my obd scanner seems to not cut it.



this is happening to me …..exactly the same thing...….you have to let off the pedal to accelerate, stomp it to the floor and it will hardly move, has trouble shifting, knock sensor code thrown...….disconnect the battery and it runs like perfectly until it does it again randomly …..a day later, a week later , whenever …..same thing everytime

did you find the fix ??
 

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