Maf causing knock sensor code theory - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

mr.nismo. · 11-03-2013, 03:54 PM

Ok. So.... When I first swapped my sr in I kept getting code 34 for knock sensor. I took a wild guess and got my single cam KA maf and swapped it. Code went away and that was it. Well recently I had multiple breaks in my harness from being old, etc, and fried my ecu. I bought another E5 ecu, put in a wireing specialties sr pro tucked harness and new knock sensor since I had it laying around. Second I started it and went for first test drive it instantly bogged. Once warmed up it bogged till 5k then opened up. So of course I thought maybe knock sensor was throwing code and sure enough it was. I reset ecu and turned it back on for 15 seconds then checked again and it was back. There were tons of breaks in my old harness and the pin that fried on the ecu was for the ignition so it could've been anything. But from my past experience could maybe this maf got shorted? I'm not around any other 240's to test so I'm just taking a stab again but consulting before I buy another maf

mr.nismo. · 11-03-2013, 08:27 PM

Any ideas anyone? I've got another maf on the way but other ideas are always great.

DMMonroe · 11-03-2013, 08:41 PM

Hope you figure it out. I had code 34 and replace the knock sensor but still getting code. After seeing this ill try a new/differnt MAF.

OnTheChip · 11-04-2013, 09:52 AM

Code 34 is specific to the knock sensor and has nothing to do with the MAF.

mr.nismo. · 11-04-2013, 10:06 AM

So brand new knock sensor brand new harness and the fact my old maf caused this problem before, you have any other ideas? Considering with my old ecu was in I had code 55

OnTheChip · 11-04-2013, 10:23 AM

Quote:

Originally Posted by dev71893

So brand new knock sensor brand new harness and the fact my old maf caused this problem before, you have any other ideas? Considering with my old ecu was in I had code 55

That was either a coincidence, or a harness problem that went away when you jiggled the harness changing the MAF (just a guess).

mr.nismo. · 11-04-2013, 10:25 AM

I guess well find out when the new maf gets here lol. I'm wondering if the maf got fucked up when the harness shorted. Idk what wire fried he ecu but if the maf wires are what did it maybe it fucked it up

mr.nismo. · 11-06-2013, 04:51 PM

Ok well it didn't fix it this time. Replaced maf, cleared so ecu flashed 55, start up for 10 seconds, recheck codes anddddd code 34

it's a fuckin new sensor and new harness. It instantly throws the damn code when the engine is turned on. Da FAQ man... It wasnt throwing a code on the other ecu

rellik27 · 11-06-2013, 05:09 PM

try another knock sensor, could just be bad even though its new.

mr.nismo. · 11-06-2013, 05:15 PM

Just weird that it would work and be ok before and now not work.

RedtopTech · 11-09-2013, 05:36 PM

Did you tighten the sensor bolt to spec? Not only will the torque have a drastic effect on knock sensor voltage ooutput but it is also very easy to damage the sensor by overtorquing

mr.nismo. · 11-09-2013, 05:56 PM

Enough to not overkill it but enough to where it won't move. I clocked it at 9 like the other one was

GeneStarWindGSW · 11-09-2013, 06:16 PM

I've had issues with new KS going bad. Make sure its a genuine OEM knock sensor (hitachi/nissan). it never came back after putting the right knock sensor on. Also overtorque can cause issues/break your KS.

last resort, this works also (did this on my last s13)
How to Bypass Knock Sensor. S13 Ka24DE OBD1 - Nissan 240SX Forums

mr.nismo. · 11-09-2013, 06:19 PM

I don't think it's an oem sensor. I guess I should replace it with one. I know I can do the resistor trick but I'm a little sketch about doin it

ultimateirving · 11-09-2013, 06:24 PM

Quote:

Originally Posted by dev71893

I don't think it's an oem sensor. I guess I should replace it with one. I know I can do the resistor trick but I'm a little sketch about doin it

Just by pass it pussy. It's easy and you don't need the knock sensor. BY the time the Ecu retards the timing from detecting knock it's probably too late anyways.

mr.nismo. · 11-09-2013, 06:25 PM

Just cause I eat pussy doesn't make me one

but agreed and I guess if it's off by 4k it's kinda useless anyways

mr.nismo. · 11-11-2013, 04:51 PM

Checked KS voltage. 4.8 in and none out. Dafuckkkkk. Guess I found the issue

muhammadki · 11-11-2013, 11:44 PM

I had code 34 and replace the knock sensor but still getting code.

mr.nismo. · 11-12-2013, 12:09 AM

Check your harness? Mine was a new (not oem) and it went out

11-03-2013, 03:54 PM	#1
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Maf causing knock sensor code theory Ok. So.... When I first swapped my sr in I kept getting code 34 for knock sensor. I took a wild guess and got my single cam KA maf and swapped it. Code went away and that was it. Well recently I had multiple breaks in my harness from being old, etc, and fried my ecu. I bought another E5 ecu, put in a wireing specialties sr pro tucked harness and new knock sensor since I had it laying around. Second I started it and went for first test drive it instantly bogged. Once warmed up it bogged till 5k then opened up. So of course I thought maybe knock sensor was throwing code and sure enough it was. I reset ecu and turned it back on for 15 seconds then checked again and it was back. There were tons of breaks in my old harness and the pin that fried on the ecu was for the ignition so it could've been anything. But from my past experience could maybe this maf got shorted? I'm not around any other 240's to test so I'm just taking a stab again but consulting before I buy another maf

11-04-2013, 09:52 AM	#4
OnTheChip Zilvia Junkie Join Date: May 2013 Location: Burgaw, NC Posts: 318 Trader Rating: (0) Feedback Score: 0 reviews	Code 34 is specific to the knock sensor and has nothing to do with the MAF. __________________ NismotronicSA - Speed-Density Tuning for Nissans

11-03-2013, 08:27 PM	#2
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Any ideas anyone? I've got another maf on the way but other ideas are always great.

11-03-2013, 08:41 PM	#3
DMMonroe Join Date: Apr 2012 Location: SoCal Age: 32 Posts: 32 Trader Rating: (0) Feedback Score: 0 reviews	Hope you figure it out. I had code 34 and replace the knock sensor but still getting code. After seeing this ill try a new/differnt MAF.

11-04-2013, 10:06 AM	#5
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	So brand new knock sensor brand new harness and the fact my old maf caused this problem before, you have any other ideas? Considering with my old ecu was in I had code 55

11-04-2013, 10:25 AM	#7
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	I guess well find out when the new maf gets here lol. I'm wondering if the maf got fucked up when the harness shorted. Idk what wire fried he ecu but if the maf wires are what did it maybe it fucked it up

11-06-2013, 04:51 PM	#8
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Ok well it didn't fix it this time. Replaced maf, cleared so ecu flashed 55, start up for 10 seconds, recheck codes anddddd code 34 it's a fuckin new sensor and new harness. It instantly throws the damn code when the engine is turned on. Da FAQ man... It wasnt throwing a code on the other ecu

11-06-2013, 05:09 PM	#9
rellik27 Zilvia Member Join Date: Jul 2008 Location: the bottom Posts: 256 Trader Rating: (4) Feedback Score: 4 reviews	try another knock sensor, could just be bad even though its new.

11-06-2013, 05:15 PM	#10
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Just weird that it would work and be ok before and now not work.

11-09-2013, 05:36 PM	#11
RedtopTech Zilvia Member Join Date: Dec 2005 Location: Virginia Beach, VA Age: 40 Posts: 293 Trader Rating: (0) Feedback Score: 0 reviews	Did you tighten the sensor bolt to spec? Not only will the torque have a drastic effect on knock sensor voltage ooutput but it is also very easy to damage the sensor by overtorquing

11-09-2013, 05:56 PM	#12
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Enough to not overkill it but enough to where it won't move. I clocked it at 9 like the other one was

11-09-2013, 06:16 PM	#13
GeneStarWindGSW Zilvia Addict Join Date: Mar 2008 Location: Central FL Posts: 719 Trader Rating: (21) Feedback Score: 21 reviews	I've had issues with new KS going bad. Make sure its a genuine OEM knock sensor (hitachi/nissan). it never came back after putting the right knock sensor on. Also overtorque can cause issues/break your KS. last resort, this works also (did this on my last s13) How to Bypass Knock Sensor. S13 Ka24DE OBD1 - Nissan 240SX Forums

11-09-2013, 06:19 PM	#14
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	I don't think it's an oem sensor. I guess I should replace it with one. I know I can do the resistor trick but I'm a little sketch about doin it

11-09-2013, 06:25 PM	#16
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Just cause I eat pussy doesn't make me one but agreed and I guess if it's off by 4k it's kinda useless anyways

11-11-2013, 04:51 PM	#17
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Checked KS voltage. 4.8 in and none out. Dafuckkkkk. Guess I found the issue

11-11-2013, 11:44 PM	#18
muhammadki Join Date: Nov 2013 Location: new york Age: 40 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	I had code 34 and replace the knock sensor but still getting code.

11-12-2013, 12:09 AM	#19
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 31 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Check your harness? Mine was a new (not oem) and it went out