My 96 Q45 is not passing SMOG TEST!!!! HELP MEEEEEEEE PLEASEEEEEEE.....

[phillo24]

Hey All, I bought me a 96 Q45 on August 12th & up to this day I haven't received my tags yet because thanks to my dealer, according to him since we bought the car from a dealership they're mainly responsible for getting it smog first before submitting the paperworks to DMV (btw that was after 2 mos when he told us)...So, now I'm getting close to my 90 days temporary tags before it expires and for the 4th time I took the car back to the dealership shop and had it checked/smog, my car always has the same result.... (NOT READY YET)...The guys on the shop told me, my car might be a LEMON It's really frustrating because the car was in good condition and only had 2 owner plus complete maintenance done...So, is my situation usual??? Is it true that all Nissan cars has problems when it comes to Smog??? What should I do??? Please help me, I need some advice guys! Thanks!!!

[Q451990]

What specifically doesn't pass? Post up your test results. When you say dealership, do you mean an Infiniti dealership, or a used car lot?

Heath

[fixer]

IF IT KEEPS COMING UP NOT READY, THAT MEANS SRT NOT COMPLETE. CK YOUR RESULTS AND SEE WHAT SYSTEM IS NOT COMPLETING, AND FIX THOSE SYSTEMS, IF YOU DRIVE THE CAR FOR 10 MILES AT LEAST THREE SYSTEMS SHOULD COMPLETE AND USUALLY THAT IS ENOUGH TO PASS SMOG TEST. O2 SENSORS , EGR AND CAT USUALLY COMPLETES FIRST. EVAP SYSTEM USUALLY TAKES LONGER. FIND OUT WHAT SYSTEMS ARE NEEDED TO PASS SMOG

[Unnatural1]

The PCM uses "monitors" to test the vehicle emissions systems. Some run continuously (when ever the vehicle is running) such as the misfire monitor. Others are non-continuous and only run when specific conditions are met. As fixer said these are things like the EGR and O2 Sensor monitors.

The PCM will run most of these monitors during a trip down the highway 5-10 miles at relatively steady speed. Usually you only need 3 of these non-continuous monitors to complete before you can pass an emissions test.

What you need to find out is which one of these monitors are not completed (or ready). It may be that you some how have not met conditions necessary to complete certain system monitors. If any of these complete and do not pass the PCM's test it will set a Trouble Code and turn on the Check Engine Light.

Your Check Engine Light is not on is it?

[Kiven422]

If your fuel pump isn't working correctly you may fail smog.

If your mileage is past 120K this is something to consider since our Q45s are known for their fuel pumps.

My 1993 Q45 wouldn't pass smog for some time. Once we replaced the fuel pump it passed with flying colors, legally. Vehicle has 234k miles on it now.

So I told my friend... he said he had the same issue with his Dodge RAM van.

Maybe you should look into this since everything else seems to be maintained in your car.

[Q45tech]

Except that a defective low PSI fuel pump would cause the engine to run very lean which would decrease CO and HC and increase NoX.

Why we need all the numbers from failed emission test to point you in the correct direction.

95% of emission failures are dirty EGR related historically.

[Unnatural1]

1996 and newer cars are not run on the dyno for an emissions test at least here in Texas. I don't know how CA handles this. Here they are simply hooked up to the inspection computer typically and the PCM is scanned for DTC's and set monitors. They may do both in CA. He's not making it pass the monitor check. If he had a bad fuel pump there is a good chance some kind of DTC would be set; lean fuel system, etc.... But, if it is not setting a code yet it doesn't matter it should still pass as long as the emissions monitors are set/ready. That's where he's got a problem it sounds like.

However, he hasn't yet mentioned whether the check engine light has come on or if there is some kind of code stored in his PCM. Nissan's do not necessarily have a problem passing emissions. My 1994 Q45 passed an emissions dyno test even with 2 bad injectors and bad knock sensors.

If they do an emissions dyno test and you've failed that then Tech is right we need the results before any of us will have any idea what is going on.

[hwyix]

I am CA BAR smog tech. Who ever sells the car in the state of CA is responsible for smog. Just take it back and get your money back. If the dealer ship puts up fuse contact BAR. They will not be happy when BAR gets involved.

As far as why it does not pass. I need much more info than your post. Scan in your smog report and post it.

[maxnix]

1996 and newer cars are not run on the dyno for an emissions test at least here in Texas. I don't know how CA handles this. Here they are simply hooked up to the inspection computer typically and the PCM is scanned for DTC's and set monitors. They may do both in CA. He's not making it pass the monitor check. If he had a bad fuel pump there is a good chance some kind of DTC would be set; lean fuel system, etc.... But, if it is not setting a code yet it doesn't matter it should still pass as long as the emissions monitors are set/ready. That's where he's got a problem it sounds like.

However, he hasn't yet mentioned whether the check engine light has come on or if there is some kind of code stored in his PCM. Nissan's do not necessarily have a problem passing emissions. My 1994 Q45 passed an emissions dyno test even with 2 bad injectors and bad knock sensors.

If they do an emissions dyno test and you've failed that then Tech is right we need the results before any of us will have any idea what is going on.

[maxnix]

1996 and newer cars are not run on the dyno for an emissions test at least here in Texas. I don't know how CA handles this. Here they are simply hooked up to the inspection computer typically and the PCM is scanned for DTC's and set monitors. They may do both in CA. He's not making it pass the monitor check.

Yeah, in WA they ran it on a dynamometer at 2500rpm and idle besides sniffing. But the state has a monopoly on that like they have on liquor.

[Unnatural1]

Even 96 and later model year vehicles? Well that sucks. That seems redundant to need to do both tests. That is what the OBD II PCM is programmed to do. Maintain like new emissions standards. But whatever.

[maxnix]

You know, I only had OBD I vehicles when I was there, so I don't really know. But I never observed any differences in testing of other vehicles. But I wasn't watching to see that either.

[Q45tech]

Early OBD2 before 2002 was very insensitive and allowed serious emission errors before the lights came on, so some states dyno test to make sure.

Necessary to catch secondary O2 tampering and high flow emission worthless cats.

[jks7188]

I failed a smog test today with my '97 Q because of the functionality component of the test, not the emissions part. For some reason, the O2 sensors, Catalytic Converter and EGR were all "pending," or not ready, during the test. Any idea what the problem is? Something computer-related?

Thanks

[hwyix]

When was the last time you changed the batter or the battery when dead?Did you clear the codes?

[jks7188]

The battery was changed at the beginning of this year, which I figured was enough time for the computer system to cycle.

The smog technician said he cleared the codes but the problem persisted. There is one code that consistently appears, U3FFF, which I guess is a body code...it might be related to the malfunctioning keyless entry system.

The one thing to note is that the check engine light appears for maybe half of a second when the ignition is turned. Would that be a computer problem?

[hwyix]

The battery was changed at the beginning of this year, which I figured was enough time for the computer system to cycle.

Yes, that is more than enough to complete a drive cycle.

The smog technician said he cleared the codes but the problem persisted. There is one code that consistently appears, U3FFF, which I guess is a body code...it might be related to the malfunctioning keyless entry system.

The one thing to note is that the check engine light appears for maybe half of a second when the ignition is turned. Would that be a computer problem?

Of course if he cleared the codes then your drives cycles are reset. Which means you must start over. Was there any pending codes? Freeze frame data?

This is a drive cycle for GM which for the most part has always worked for me on all my customers cars.

General Motors Driving Cycle

A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run. 2. Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim. 3. Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed. 4. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed. 5. Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed. 6. Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3. 7. Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst. 8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

If your still having problems come by my shop in san mateo and I will look at itfor you.

Sean

[fixer]

if you drove the veh more than 20 miles and all your systems is not complete, ou should ck your ecm to see if someone left it in test mode. most shops that dont have a scanner can access dtc by turning a screw in the ecm to activate test mode. i personally have never used this method so i dont know if you can not leave it in test mode. it wound be wort it to ck. the nect thing that i would check is if the engine is warming up completely. usually the o2 and cats take a few minutes but after engine is warmed it completes during a road test.

[Unnatural1]

The battery was changed at the beginning of this year, which I figured was enough time for the computer system to cycle.

The smog technician said he cleared the codes but the problem persisted. There is one code that consistently appears, U3FFF, which I guess is a body code...it might be related to the malfunctioning keyless entry system.

The one thing to note is that the check engine light appears for maybe half of a second when the ignition is turned. Would that be a computer problem?

A body DTC shouldn't make a difference for an emissions inspection. A powertrain or P-code DTC would definitely be a problem. But, if he cleared all DTC's and then tried to run an emissions test he is an idiot. As mentioned above, when the DTC's are cleared the monitors are also reset.

All the info hwyix posted is useful. But, the easiest way to set monitors on most cars (without thinking about it) is to simply drive them about 15-20 miles. For many vehicles 15-20 miles on the highway at a relatively steady cruise will set enough of the monitors to pass a state emissions test. Of course, the criteria to set monitors very from manufacturer to manufacturer, this is usually enough to set the majority of the monitors.

~Brendan

[hwyix]

Driving 15-20 miles right after you cleared your codes will not workon a lot of cars. I do this for a living. I did not take scientific studyand write down which cars monitors cleared right after a short little tripon the freeway and which ones did not. But I do know it was veryvery common for a lot of the monitors to not run on a lot of cars.

Here is one the big ones right here. Some cars require multiple trips. But a lot of trips on some cars do not count unless it is a COLD start. Meaning thecoolant temp sensor gets below X. So, driving some cars 100 times ina row for 10,000 miles and never letting the temp sensor get cold some of the monitors will not run.

"1. Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run."

[Q45tech]

FSM has detailed crank, warm up, speed proceedures to process system ready.................usually requires 50 miles and at least 3 cold starts.

[hwyix]

FSM has detailed crank, warm up, speed proceedures to process system ready.................usually requires 50 miles and at least 3 cold starts.

ding ding we have a winner!

So follow the fsm it should be very close to what I posted above and do it over three days.

thank you.

[hwyix]

FSM has detailed crank, warm up, speed proceedures to process system ready.................usually requires 50 miles and at least 3 cold starts.

very nice. thank you.

ding ding we have a winner!

So follow the fsm it should be very close to what I posted above and do it over three days.