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Smog check problem

1996 Nissan XE P/U, standard trans, 163,000 mi,new battery 4 mo ago, driven approx 20 - 40 mi/day. At smog test, result was “Rejected.” (not “Failed”) Report said OBD catalyst, OBD evap, OBD exhaust gas, & oxy sensor tests “Not Completed.” The connector is not damaged. No aftermarket wiring is present. No one has touched the connector since I had a ck eng lite (more than 90 days ago). Plates renew very soon. Help! Thanks.

When a battery is disconnected the readiness monitors need to be reset by performing what is called a drive cycle. A drive cycle means the vehicle must driven under specific conditions in order to reset the monitors. Here’s the drive cycle for your vehicle.

Engine cold.

O2 sensor heater monitor: Start engine and let idle for 1.5 minutes.

EGR monitor: Drive 3 minutes in 4th gear varying the speed so RPM’s are between 1800-2200 RPM’s and with the A/C on. Drive 1.5 minutes @ 55-65 MPH 1800-3000 RPM’s in 5th gear. Stop the vehicle and allow the engine to idle for at least 10 minutes. Then immediatly start driving the vehicle.

Catalyst monitor: Drive 3 minutes @ 50-60 MPH in 4th gear. Keep RPM’s above 3,000. Allow speed to vary if required.

O2 sensor monitor: Drive 3 minutes @ 53-58 MPH in 5th gear with A/C on. Stop vehicle and allow engine to idle for 1 minute.

EVAP Monitor: Drive 2 minutes with engine RPM’s at about 3,000 RPM’s in 3rd gear. Accelerate to 44 MPH. Deccelerate to 38 MPH. Accelerate to 44 MPH. A/C off Do not completely release the accelerator… Stop the vehicle and allow the engine to idle for 1 minute. Drive 2 minutes at a steady speed of 31-44 MPH in 4th gear. A/C off. Hold accelerator as steady as possible.

End of drive cycle.


What was your check engine light for and what did you do to fix it? Your computer has a slot in the side of it that you can use a screwdriver to pull codes with and reset the computer. If someone used this and didn’t return the slot to the proper position, the computer will not complete its tests.

Its unlikely that anyone would use this slot as it is extremely difficult to get to, but on the off chance someone did, that is a possibility.

This Nissan pickup is a 1996. OBDII so there’s no slot on the computer to turn to pull the codes. Unlike my 1995 Nissan pickup which is OBDI, the computer under the passenger seat does have a slot to turn to pull the codes.


Thank you very much for your detailed response. I will try it. I forgot to put down that I had to remove the fuse for the horn bcuz the horn was sounding randomly at some right and left turns. Would that fuse being out have anything to do with the connector module? Btw, it’s funny that I had this particular problem bcuz I’m a test driver and some of the cars we test run on OBD II drive cycles (much less complicated ones). Thanks for your help.

Thank you for your response. I never figured out what the ck eng lite was for. I went to Auto Zone and they weren’t able to get a reading. Previous times when I had ck eng lites, they always were able to get a reading, but not this last time. After some repair work was done on the truck, the eng lite was out and never came back on.

Find out what fuse is for the ODB-II connection. It is a powered slot, and will prevent a reading if there is no power going to it. I’ve had this problem on occasion, and need to replace the fuse to get the codes read.

Yeah, it was a blown fuse that kept my 97 Explorer from passing smog.

Interestingly -since your horn fuse is removed- the fuse was the PCM “keep alive memory” & horn relay fuse.

Replaced the fuse & drove it for a week to reset the monitors. It then passed Ca.smog no problem

Replace the fuse and just disconnect the horn…