bored smog tech here

[ryguy]

Dear Mr. Smog Tech,
My S13 failed NOx last week. Is it likely that it failed because of my 3" exhaust? I have heard that the lack of backpressure doesnt let the EGR operate properly. Any insight into this?

[grnappletree14]

i have a ?. im putting my ka24de s14 back into my s14 its a 95. i want to know if i can pass smog with some header i have. i believe they are obdx headers they have the egr value connectors and so if i install before i drop it in will it pass smog, or would it be better to just put on the regular exhaust manifold and pass smog and then change it?

[murda-c]

When you plug into an OBD2 motor, does it give you information on what type of motor it is?

I'm just wondering if i swap for another obd2 motor and i get it running properly and not throwing codes if they'd even notice.

[techn9ne]

Originally Posted by ryguy

Dear Mr. Smog Tech,
My S13 failed NOx last week. Is it likely that it failed because of my 3" exhaust? I have heard that the lack of backpressure doesnt let the EGR operate properly. Any insight into this?

+1 internets

[techn9ne]

Originally Posted by grnappletree14

i have a ?. im putting my ka24de s14 back into my s14 its a 95. i want to know if i can pass smog with some header i have. i believe they are obdx headers they have the egr value connectors and so if i install before i drop it in will it pass smog, or would it be better to just put on the regular exhaust manifold and pass smog and then change it?

it depends. if you get mr by the book smog tech, he will look at the headers and look for a CARB exemption # or an EO (executive order) #. if those arent there, he will fail it on the spot.

if you get the guy that doesnt really care, as long as he sees that the headers have the egr valve connectiors and all the vacuum lines and shit are connected, he probably wont give you grief.

i would just throw on the normal exhaust manifold just to be sure, since your already throwing a whole new engine into the KA, then just swap it later.

[techn9ne]

Originally Posted by murda-c

When you plug into an OBD2 motor, does it give you information on what type of motor it is?

I'm just wondering if i swap for another obd2 motor and i get it running properly and not throwing codes if they'd even notice.

some obd 2 pcm's will tell you the VIN number of the car they originally came in. but the only thing the smog machine checks for is readiness monitor status and diagnostic trouble codes.

[GSXRJJordan]

+a shit ton for this thread. Thanks a bunch man

[shade]

What does the visual check comprise of? I'm practically asking for the whole procedure. I might just do what HyperTek said earlier.

[SilviaS132008]

Dude, ok my 240 doesnt turn over, its been sitting for a year. what you think is the problem??

[slipin101]

Dear smog tech
i justa had a smog but failed
heres the list of wat i failed...........

fuel evaporative control funtional
MIL/check engine light

everything else is good.

how can i fix that? i know its a leak but how would i go by finding it, i tracked it down to the rear end of the car but no luck finding it. HELP!! need smog ASAP

[techn9ne]

Originally Posted by shade

What does the visual check comprise of? I'm practically asking for the whole procedure. I might just do what HyperTek said earlier.

heres how most smog techs run the visual. they pull the car in, pop the hood, and read the vehicle emissions control information sticker on the underside of the hood. (if you dont have one, we have a manual that tells us the timing specs, emissions components, etc on every car. we're just too lazy to look at it.) theyll jot down the timing spec, engine size, and emissions components they'll look for on their notepad or whatever, along with the mileage, etc. then your car gets put on the dyno. after the dyno run, the computer asks us to inspect (if applicable) the air injection. so pre-94 240's better have the pulse air shit hooked up. then, we look at the pcv, ignition controls, oxygen sensors, fuel rail/injectors, egr valve, vacuum lines, wiring, look for smoke coming off the engine or out of the tail pipe (new test will fail you for visual smoke), liquid fuel leaks, etc. then it asks if the check engine light is on. 95 and older cars will only fail if the mil is on and the smog tech enters that it is on. 96 and newer fail that test automatically, thanks to obd2. then it asks to check idle speed, and timing.

however, alotta smog techs are lazy as fuck, or if the smog joint is busy, they will not even bother to give the engine a second glance and will just pass everything on the visual.

but generally, you'll have Mr. 'merican performance chevy 350 master, who generally doesnt know what and SR looks like. and if he doesnt bother looking at the engine because "its a goddamn piece of shit rice burner," and "all these 4 bangers are the same"

[techn9ne]

Originally Posted by SilviaS132008

Dude, ok my 240 doesnt turn over, its been sitting for a year. what you think is the problem??

check your blinker fluid and muffler bearing.

[techn9ne]

Originally Posted by SilviaS132008

Dude, ok my 240 doesnt turn over, its been sitting for a year. what you think is the problem??

if that doesnt work, try making sure your rotary seals aren't blown.

[techn9ne]

Originally Posted by slipin101

Dear smog tech
i justa had a smog but failed
heres the list of wat i failed...........

fuel evaporative control funtional
MIL/check engine light

everything else is good.

how can i fix that? i know its a leak but how would i go by finding it, i tracked it down to the rear end of the car but no luck finding it. HELP!! need smog ASAP

the evap control functional is that test where they hook that hose up to your gas tank, pinch the line going from the tank to the canister, and pressurize it.

i would check all the rubber hoses connecting from the gas tank up front to the charcoal canister, then the filler neck on your gas tank.

the check engine light on a pre-obd2 car is an insta fail. so try pulling the code off the ecu and go from there.

[240trooper]

Originally Posted by techn9ne

if that doesnt work, try making sure your rotary seals aren't blown.

they might need to rotate the headers allso,

[dynamicck]

mr. smog tech, I think you should pull the info of where you work off this thread or other threads, and your location.
I would hate to see this thread get into the wrong hands.
Never learned half this info from anywhere else.
+1 for you.

[techn9ne]

Originally Posted by dynamicck

mr. smog tech, I think you should pull the info of where you work off this thread or other threads, and your location.
I would hate to see this thread get into the wrong hands.
Never learned half this info from anywhere else.
+1 for you.

im not worried about it. im helping people pass legitimately, i dont see anything wrong about it.

[proud2b3black]

from what i read earlier it said that if i remove the light bulb for the check engine light then my car can pass smog? im not getting it exactly cause im really looking for a place to smog my car non-legally but if thats all i have to do then let get that done. i know that the check engine light is part of the visual inspection part only so how else would it fail?

1996 zenki 240sx

[techn9ne]

Originally Posted by proud2b3black

from what i read earlier it said that if i remove the light bulb for the check engine light then my car can pass smog? im not getting it exactly cause im really looking for a place to smog my car non-legally but if thats all i have to do then let get that done. i know that the check engine light is part of the visual inspection part only so how else would it fail?

1996 zenki 240sx

for your car, since it is obd2, you cannot pull the check engine light bulb if it is on. 96+ cars we plug into the smog machine and it reads codes directly from the ecu. and you cannot just disconnect the battery either, since the machine will fail you for having incomplete readiness monitors. and to expand a little more, on 95 and older cars, if the check engine light is on, you automatically fail the inspection. if the check engine light doesnt work, you automatically fail the inspection. both of these rules apply to all cars, but since we dont plug 95 and older cars into the smog machine, and the bulb is off, (disconnected or not lit) and the guy does not bother to check if it works, then you will at least have a chance to pass, as long as your car runs the rest of the test fine (visual and tailpipe)

[S-Nation S13]

Originally Posted by twistedsymphony

+1 to this... "astute" techs will notice that the CEL doesn't come on when the car goes through the self test... notice when you first turn the car on all the warning lights come on... this is so you can check if the bulbs are dead. wiring up the CEL to the oil light works great because it will come on with the self test and then go off once the car is up and running.

There are things you can do to the Auto ECU to prevent it from throwing a code, I haven't done it but I've heard its not too difficult, Manaul ECUs go on eBay and the BST all day for $60...



not sure what years yours is but there's a nissan sticker on it with two big letters cross reference those to figure out what it is

Automatic ECUs
11 = 89-90 240sx AT (KA24E) ?
15 = 89-90 240sx AT (KA24E) Cal
25 = 91-94 240sx AT (KA24DE) ?
29 = 91-94 240sx AT (KA24DE)
HU = 95 240sx AT (KA24DE) (mfg before 10/94)
3D = 95 240sx AT (KA24DE) (mfg after 9/94)
CB = 96 240sx AT (KA24DE) Universal
NF = 97-98 240sx AT (KA24DE)
J7 = 97-98 240sx SE AT (KA24DE) (A18-H64 GA4)

Manual ECUs:
10 = 89-90 240sx MT (KA24E) ?
24 = 91-94 240sx MT (KA24DE) ?
28 = 91-94 240sx MT (KA24DE)
HT = 95 240sx MT (KA24DE) (mfg before 10/94) (A18-E07-G90)
3C = 95 240sx MT (KA24DE) (mfg after 9/94)
CA = 96 240sx SE MT (KA24DE) (A18-E27-G46)

^thats a list I've been working on, it's not complete so if you've got something else then you'll need to google about. My car has "HU" because it's an early model 95 with an AT ecu...

i know i know off topic but was wonderin sorry to kill thread
was wondering mine has a EP on it and mine is manual 93 ka24de is there anyway to confrim this ecu actin all wierd

[nysmo240]

Waddup? I have a 96 S14 that passed the emissions test but failed becuz the CEL wouldn't come on. The smog tech said that my ECU wasn't throwin any codes eithr so I though it was a burnt bulb. I then bought a bulb from Nissan and just swapped it out with the old one, and still no light. I unplugged the battery for a good several seconds and reconnected, but still no light. I also put the ECU in diagnostics mode and then had it reset, but still not light. Any ideas?

Also, some of the guys here wrote about rewiring it to the oil pressure light...can anyone tell me how u do that and which wires to rewire on the back of the instrument panel? I'll also be lookin it up in my manual in the meantime to try to figure it out.

Thanks.

[nysmo240]

NVM...for some reason...it's now working. I'm not sure if this may be why, but I stuck a wire from the the oil pressure wire to the CEL wire and then it came on, and stayed on after i removed the wire...maybe it just needed a jumpstart..haha.

[redline racer510]

my speedo in my s13 doesnt work will this be an issue in my next smog test??

[techn9ne]

Originally Posted by nysmo240

Waddup? I have a 96 S14 that passed the emissions test but failed becuz the CEL wouldn't come on. The smog tech said that my ECU wasn't throwin any codes eithr so I though it was a burnt bulb. I then bought a bulb from Nissan and just swapped it out with the old one, and still no light. I unplugged the battery for a good several seconds and reconnected, but still no light. I also put the ECU in diagnostics mode and then had it reset, but still not light. Any ideas?

Also, some of the guys here wrote about rewiring it to the oil pressure light...can anyone tell me how u do that and which wires to rewire on the back of the instrument panel? I'll also be lookin it up in my manual in the meantime to try to figure it out.

Thanks.

there might not be power/ground going to the wires that turn that bulb on. the light should come on if the key is in the on position but the car is not on.

[techn9ne]

Originally Posted by redline racer510

my speedo in my s13 doesnt work will this be an issue in my next smog test??

as long as the check engine light is not on, you should be fine.

[soreballz]

My girls car...
91 S13.
95 KA-DE.
New cat.
Timing is perfect.
Recently Seafoamed to clear the carbon deposits.
New plugs, wires, cap and rotor.
EGR works perfectly...

Nox is STILL 6 times over the legal limit. Any ideas?

[flclsteve]

Originally Posted by soreballz

My girls car...
91 S13.
95 KA-DE.
New cat.
Timing is perfect.
Recently Seafoamed to clear the carbon deposits.
New plugs, wires, cap and rotor.
EGR works perfectly...

Nox is STILL 6 times over the legal limit. Any ideas?

im sure u changed the o2 sensor with the new cat right?

off topic
new plugs and wires still misfiring gonna try a new cap n rotor tommrow too and i also need to check timming

[techn9ne]

Originally Posted by soreballz

My girls car...
91 S13.
95 KA-DE.
New cat.
Timing is perfect.
Recently Seafoamed to clear the carbon deposits.
New plugs, wires, cap and rotor.
EGR works perfectly...

Nox is STILL 6 times over the legal limit. Any ideas?

does she have heinous 3" exhaust? (the car) is the backpressure valve working correctly? is the pulse air hooked up? what test is it failing for?

[MrChow]

Wurd. Good oil change? ^^ What did you fail at...

I pass well with.
S14 95 KA
Stock cat
3' exhaust
AEM intake

[flclsteve]

Mr smog tech.
I have a 97 honda civic witch just got approved for assistance with smog repair fees it failed for high Nox during the 15 mile per hour run
any idea what it might be its a bone stock car