Knock Sensor questions

redmaro · 05-10-2007, 06:09 PM

I have a check engine light, so I did a diagnostic and I got code 52 for knock sensors. One knock sensor (front sens.) was broken so I went to a junk yard and pulled one off another toyota (dont remeber what car). It fit fine, I just had to rewire it. But im still getting code 52, the check engine light is almost always on, even when the car is at idle. Ive also noticed that at full throttle the car dosent pick up after 80-90mph like before, it slows down alittle.

IHateHacks · 05-10-2007, 07:01 PM

If you didn't get a knock sensor from a supra, then you are using the wrong one. I don't care if it physically fits or not, it doesn't have the resistance values that a supra knock sensor has.

Go to the dealer and buy a knock sensor for your specific vehicle.

redmaro · 05-10-2007, 07:23 PM

Do you think that the knock sensor has anything to do with my car slowing down after 80mph?

Ill get the knock sensors fixed anyways thanks.

supramacist · 05-10-2007, 07:33 PM

You may also want to change your' o2 sensor, in the exhaust manifold.
From what I understand, not from experience, The o2 sensor will reak havoc with your throttle response.

Staceman · 05-10-2007, 11:43 PM

Did you re-set the codes in the ECU after you replaced it the first time?

j3pz · 05-11-2007, 12:44 AM

after you fix the problem, you have to reset the ecu to clear codes. to do this pull the 15amp efi fuse in the engine compartment for like 30seconds. if that doesnt clear it than you still have a problem

dannydavi · 05-11-2007, 06:50 AM

i had a pretty bad o2 sensor and my throttle response still seemed up to par. and when i reset my codes i just took the positive cable off the battery for a few minutes and they have yet to come back... i would advise doing that then testing again every couple hundred miles. good luck

Staceman · 05-11-2007, 02:17 PM

Gotta reset your clock and stereo stations disconnecting the battery. Still works, as does removing the EFI fuse.

supramacist · 05-11-2007, 03:03 PM

Quote:

Originally Posted by dannydavi

i had a pretty bad o2 sensor and my throttle response still seemed up to par. and when i reset my codes i just took the positive cable off the battery for a few minutes and they have yet to come back... i would advise doing that then testing again every couple hundred miles. good luck

Ya, that's why I made note that it was what I had heard and not experienced.

Thanks.

redmaro · 05-11-2007, 04:38 PM

Yeah Ive reset the ecu various times. Ive bought two knock sensors already hopefully Ill have them by next week. Thanks guys.

05-10-2007, 06:09 PM	#1
redmaro walbro fp Join Date: Mar 2006 Location: arizona Posts: 432	Knock Sensor questions I have a check engine light, so I did a diagnostic and I got code 52 for knock sensors. One knock sensor (front sens.) was broken so I went to a junk yard and pulled one off another toyota (dont remeber what car). It fit fine, I just had to rewire it. But im still getting code 52, the check engine light is almost always on, even when the car is at idle. Ive also noticed that at full throttle the car dosent pick up after 80-90mph like before, it slows down alittle. __________________ MK3, Auto, Turbo.

05-10-2007, 07:23 PM	#3
redmaro walbro fp Join Date: Mar 2006 Location: arizona Posts: 432	Do you think that the knock sensor has anything to do with my car slowing down after 80mph? Ill get the knock sensors fixed anyways thanks. __________________ MK3, Auto, Turbo.

05-11-2007, 12:44 AM	#6
j3pz 500whp yet? Join Date: Nov 2005 Location: Mechanicsville, MD, US of A, 20659 Posts: 1,060	after you fix the problem, you have to reset the ecu to clear codes. to do this pull the 15amp efi fuse in the engine compartment for like 30seconds. if that doesnt clear it than you still have a problem __________________ 88 N/A w/ 5spd - stock - not running, bhg 87 turbo/targa w/ 5spd- fidanza light weight flywheel, new oem slave cylinder, apexi air filter, no ac and no heat

05-11-2007, 06:50 AM	#7
dannydavi 12psi boost Join Date: Mar 2007 Location: Sacramento, Ca Posts: 373	i had a pretty bad o2 sensor and my throttle response still seemed up to par. and when i reset my codes i just took the positive cable off the battery for a few minutes and they have yet to come back... i would advise doing that then testing again every couple hundred miles. good luck __________________ '86.5 Supra - A/T - N/A - JDM Useful Sites: ToyoDIY.com ToyotaPart.com MKIIITSRM

05-11-2007, 04:38 PM	#10
redmaro walbro fp Join Date: Mar 2006 Location: arizona Posts: 432	Yeah Ive reset the ecu various times. Ive bought two knock sensors already hopefully Ill have them by next week. Thanks guys. __________________ MK3, Auto, Turbo.

05-10-2007, 07:01 PM	#2
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	If you didn't get a knock sensor from a supra, then you are using the wrong one. I don't care if it physically fits or not, it doesn't have the resistance values that a supra knock sensor has. Go to the dealer and buy a knock sensor for your specific vehicle.

05-10-2007, 07:33 PM	#4
supramacist 1000whp postwhore Join Date: Apr 2007 Location: Escape from the Prison Planet Posts: 1,356	You may also want to change your' o2 sensor, in the exhaust manifold. From what I understand, not from experience, The o2 sensor will reak havoc with your throttle response.

05-10-2007, 11:43 PM	#5
Staceman Intake Join Date: Nov 2006 Location: Phoenix, Az. Posts: 48	Did you re-set the codes in the ECU after you replaced it the first time?

05-11-2007, 02:17 PM	#8
Staceman Intake Join Date: Nov 2006 Location: Phoenix, Az. Posts: 48	Gotta reset your clock and stereo stations disconnecting the battery. Still works, as does removing the EFI fuse.

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