# failed smog check due to ecu



## payk (May 5, 2004)

has anyone had this happen, my car didn't pass CA emisssions test because of an old cat, AFTER changing to a new cat and new o2 sensors and reseting the ecu, the smog tech says the car failed because ECU "not ready or something" has that happen to anyone before? The smog tach says to drive it around for a day then come back to retest.. anyone have any ideas?


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## OmegaManEX (Oct 4, 2002)

yep you failed because you reset your ecu before the test . When you reset the ecu it has to redo all the rediness tests , so until the ecu completes these checks it will read as "not ready" . All you have to do is drive the car around like normal for maybe a week and it should be done. ..or your other option is to complete the ready checks yourself by performing specific tasks, which i am unfamilir with , maybe someone else can help with that.


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## lshadoff (Nov 26, 2002)

I had this problem last year, and posted this message to the SE-R Mailing List:

The 1996 & 1997 200SX SE-R is noted as being particularly difficult to set the EVAP and catalytic converter readiness test.
(1) http://www.babcox.com/editorial/us/us50326.htm
(2) http://www.dmvstat.com/pdfforms/ecnews1st03.pdf

There is a Drive Pattern which will set the monitors, but it varies from one vehicle to another. See (1) above.

I found that there is a Nissan Technical Service Bulletin 98-018C which contains the drive patterns for certain vehicles including the 200SX SE-R and the Sentra/200SX GA18. I joined AllData (http://www.alldata.com/) and downloaded the drive patterns for the 200SX SE-R. It works, but you must follow the directions EXACTLY. That means starting with a cold car and driving as instructed. I only needed to have less than three monitors set, so I started with a cold car, drove to a nearby expressway, and started with #4. It set the 02 Sensor and Catalyst in one pass!

Here are the instructions. They must be performed EXACTLY as indicated.:

200SX SE-R Auto Trans
1. Engine coolant less than 158º. Start and idle 1.5 min.
2. Drive with RPM 1300-1500, D(OD ON), AC ON, constant load*, 3 min.
3. THEN 50-70mph, 1800-2000rpm, D(OD ON), constant load*, 1.5 min.
4. Idle for 10 min., then switch off, then restart
5. IMMEDIATELY Cruise Control 50-60mph, D(OD OFF), >3000rpm, no deceleration**, 3 min.
6. THEN Cruise Control 53-58mph, D(OD ON), 2100-2500rpm, AC ON, no deceleration**, 3 min.
7. D(OD OFF), decelerate no gas at least 5 seconds, then idle 1min in park

* I assumed it is constant load, but the instructions say "B/F SCHDL 2.3-2.5 msec" for #2 and "2.0-3.5 msec" for #3.
**No deceleration for more than 3 sec. or you must start over with a cool car.

200SX SE-R Manual Trans
1. Engine coolant less than 158º. Start and idle 1.5 min.
2. Drive with RPM 1800-2200, AC ON, constant load*, 3 min.
3. THEN 50-59mph, 2000-2800rpm, constant load*, 1.5 min.
4. Idle for at least 10 min., then switch off, then restart
5. IMMEDIATELY 50-60mph, 4-th Gear, >3000rpm, 3 min.
6. THEN Steady State Cruise 53-58mph, 5-th Gear, 2500-2700rpm, no deceleration**, AC ON
7. Downshift, decelerate no gas at least 5 seconds, then idle 1 min. in neutral

* I assumed it is constant load, but the instructions say "B/F SCHDL 1.5-1.7 msec" for #2 and "2.0-3.0 msec" for #3.
** No deceleration for more than 3 sec. or you must start over with a cool car.

1,2, &3 – O2 Sensor Heater and EGR
4 through 7 – CATALYST and O2 Sensor

The car does not give any visual indication about the Readiness Test, so I used my EASE Diagnostics OBD-II program for my laptop computer. It plugs into the OBD-II port under the dash and reads out, among other things, the Readiness status. I drove through the drive pattern with it connected, and could see whether the sensors were set.

On my car, when the engine is turned off and turned back on, those three sensors read Not Ready again, and I had to go through the pattern, drive directly to the test station, and leave the car running through the entire emissions test.

Lew


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## payk (May 5, 2004)

*ecu readiness smog failed*

that helps a lot
im gonna try all that !!!!
i guess its the sameor close to it for a ga16de
does it matter how far one drives
cause im a courier and use the car a lot at least 85 mile a day
street and fwy driving combined

thanks a lot


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## BlendNo27 (May 4, 2004)

i sticky vote this...


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## lshadoff (Nov 26, 2002)

payk said:



> that helps a lot
> im gonna try all that !!!!
> i guess its the sameor close to it for a ga16de
> does it matter how far one drives
> ...


I found that you must follow the procedure exactly. Any deviation and the readines test is not set.

The Texas requirements are that there can be no more than 2 readiness tests unset. So, I just did steps 4 through 7. I drove to a nearby expressway and stopped by the side. Then I idled for 10 min (Step 4) and drove off down the expressway. If I encountered any traffic which disrupted the procedure, I had to start over from step 4. It's a real PIA!

Lew


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## payk (May 5, 2004)

*ecu failed smog*

i borrowed an obd 2 scanner from autozone (free with deposit) 
it does show the readiness tests on there 7 for the nissan
its showing misfire test, ready, ho2 ready, evap ready, o2 not ready, egr not ready, catalyst not ready
ive been driving around for 4 days still no change
i've tried those steps by lew but its hard to keep up
any other suggestions
i've replaced my rear 02 ,and post cat
should i replace the 3 way cat too


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## lshadoff (Nov 26, 2002)

payk said:


> i borrowed an obd 2 scanner from autozone (free with deposit)
> it does show the readiness tests on there 7 for the nissan
> its showing misfire test, ready, ho2 ready, evap ready, o2 not ready, egr not ready, catalyst not ready
> ive been driving around for 4 days still no change
> ...


Replacing parts is not going to help unless you have a Check Engine light for that component. The procedure is the only way. My local Nissan dealer said that it may take months for them to set by themselves. The procedure is the only thing that worked for me. Steps 4 through 7 should set all but one for you.

Lew


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## payk (May 5, 2004)

*failed smog due to ecu*

apparently the ga16 is easier to reset because i just drove it a lot with the ac on. i tried doing the 50-60 mph for three minutes the releasing the gas 
but never really had the chance to slow to 20 mph but after a while
the MIL light can on again and it states catalyst efficiency below standards
so in other words i have to replace my precat (exhaust manifold ) it costs an arm and a leg but it is a necessity i have 190000k miles on it orig engine
so yeah at least i saved on the cat (post Heated o2

thanks


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