4 sets of error codes 12-33-34-41 on a 95 240sx

[komete]

Hello all, I hope I'm posting this in the right section. I recently got a used MAFS to replace my old broken one. Now the car is running great. I would say it's running like it did 6 or 7 years ago. But I'm getting a lot of error codes. 12-33-34- and 41.

Here is the story. engine would want to die at anything over 2000 rpm's. Meaning a bad Maf sensor. I took it to the dealership and they said the computer gave a bad o2 and knock sensor code. I changed the o2 sensor. Still trying to figure out where the knock sensor exactly is but it's next. Later on I discover it's a bad maf so I replace it. Cars running great. So today I decided to reset ecu to see if maybe that would clear up the check engine light. Well it spat out these 4 codes

12- mafs.. hello it's working great?31- ecm.. aint taht rediculously expensive?33- front 02 It's brand new???34- knock sensor <- I'm looking for you41- air intake air sensor.

Only thing I can think is I had a power steering leak and it spit out power fluid on the side of the engine. I drove it a while like this before I relized all I had to do was tighten the tube. could the wires be dirty giving all these error codes?

Any and all advice besides selling my car would be appriciated. I wanted to deck a coworker yesterday for suggesting I sell it since it's running great. I lub my 240..

Did I mention I need to get an inspection sticker like 6 mos ago?

[EstoMax]

the only code i have dealt with of the above there is the knock sensor one (34)

mine started to trip every day for some reason (with code 103, the neutral switch, they always come togther its wierd) and i got a new knock sensor harness (20$ at courtesyparts), now it only trips every few weeks, im a pro at resetting the CEL lol.

replacing the knock sensor itself is a ***** though, you pretty much gotta remove ur intake mani to do that, its right under it. the wire to it i magically got off and on by poking at it with a sharp edged stick.

the knock sensor CEL doesnt make the car run any different, at least i dont feel a difference

hope this helps

[komete]

Thanks Estomax for the input. Quick question if I'm standing right infront of the engine looking at it is the knock sensor front right low? I'm going to go after that bish tomorrow I just wanna know where to look. I have a pdf manuel of my 240 but it's poo. Here is a pic of of it telling me where the konck sensor is. It's so vague.

[EstoMax]

yea man its under the intake manifold runners, you gotta move the fuel line out of the way to see it well really, but its down there with a wire coming out of it.

i dont think i got a picture of it but i could take one tmrw or something, your not gana have fun taking it off with the intake mani on lol. if you figure something out tho let me kno

marko

[komete]

well I'm going to go out there ina few and and search that bish out now I know just about where it is. I was thinking it wasn't far from the exhaust manifold because of that 1st picture. Now I see it's on the other side of the engine below the throttle body.. Can I say suck?

[komete]

I was reading up on our FAQ section and I'm wondering if the ALL the ecu codes are just being stored from before. I have unplugged the maf sensor, air flow sensor, and started the car. So maybe it's giving me those errors from before. I did also replace replace the o2 sensor. only thing I havnt touch is the knock. BTW the 31- ecm error has gone away. I think I'll wait a few weeks and start checking again after I reach 50 cranks.

From the FAQ "Malfunction Codes are stored by the ECU for 50 times of cranking the starter. Then they are erased. If the same conditions are present, the Malfunction Code will be stored again for 50 cranks of the starter. And so on..."

[EstoMax]

to erase the codes just go into diagnostic mode and then out of diagnostic mode and then into diagnostic mode (u will get 55 at this point) and then out of it.

that will clear all codes

marko

[KFL]

Correct If you unplug IE: Maf sensor without disconnect battery it will throw a code..You can just disconnect the battery and wait a few minutes 10min.From that pic just follow the harness it leads to the ks which is on the side of the block. It's a pita to remove like stated, my old 95 had the issue. I did it though without removing the intake manifold swivels,etc.

[HashiriyaS14]

I've got a code 41 that I can't get rid of right now.

I've got an aftermarket short-ram, which might have something to do with it, but 2BN_S13 and I have futzed with it several times now, and we now think that it's a problem with the wiring for the Air Intake Temp Sensor, rather than the sensor itself.

Anyone else ever had an issue with this, where they replaced that sensor but still pulled a code?

[komete]

Esto you are on my xmas list.. I got a 55 it's all ok now. First time ina long time no check engine light while I'm driving.. good stuff.

[EstoMax]

glad to be able to help someone out!

now ull just have to see to find out if the cel will pop again.. u can become a pro at resetting it like me haha

[komete]

Hope I'll be able to return the favor

[jmhalder]

yeah, actually it did seem that replacing my knock sensor did affect performance, apparently it retards timing in some of the band up to 4 degrees. which is noticable. it will also save gas. just go to http://www.zcontrol.net and rig up a consult interface. then use your trusty laptop to check codes, and erase them... unplugging my battery doesnt seem to erase my codes. maybe its just me.

[Dattebayo]

If you've got all those codes and a ecm code showing, you may need to replace the engine computer itself.

as far as I know, ECM = ECU = engine computer you got the codes from. They are pretty cheap from your local pick 'n pull junkyard...