Q45/94 (122k): Emissions Results?

[Mint Q45A]

I did the required Emissions Testing today - these were the results:

HC (PPM) Limit ~ ResultCruise: 150 ~ 31Idle: 220 ~ 20 CO (%) Limit ~ ResultCruise: 1 ~ 0.04Idle: 1.2 ~ 0.01

Obviously a: PASS.

Out of curiosity: Are these results comparable to what other Q with similar milage are getting?

I assume there will always be differences associated with the testing equipment, the ambient conditions, altitude, etc...

[goody90q45]

......Out of curiosity: Are these results comparable to what other Q with similar milage are getting?

I compared your results to my CA printout from July and your engine looks to be running very clean. The CA printout gives a statewide average for each emissions gas tested and it's based on similar 8 cylinder engines, and quite possibly just Q45 engines. Here's my comparison:

HC Idle.... (15mph) WA Max 220...CA Max 80...Ave 21...You 20...Me 79HC Cruise (25mph) WA Max 150...CA Max 45...Ave 13...You 31...Me 44

CO Idle.....(15mph) WA Max 1.2..CA Max .46...Ave .06...You .01...Me .12CO Cruise (25mph) WA Max 1.0..CA Max .42...Ave .05...You .04...Me .05

It looks like your Q is running well even when compared to CA's tight standards. I barely passed our smog test (HC) and will have to do some fixes if I expect to pass in 7/09. My NO emissions were also very high on the test. All my injectors ohm good but my gas mileage is down. I suspect that the new O2 sensors I installed before the test may not be operating properly (per Nissan Data Scan). Any ideas?

Sorry to threadjack but at least you can now enter CA with a clear consciounce.

[3Q Jay]

Mike- replacing your t-stat will help (i know you said it had gone missing).must get engine/cats nice and hot to keep the HC down.i didn't take my own advice on the FY33 last month and pegged max limits (still a pass though). next time i will do more redlines the day before/ day of test, followed by some nice high speed but steady cruise just before the sniffer goes on.

[Mint Q45A]

Mike,I don't have one good tip, but these are some of the things I do/use or have recently done. It may be a combination of things, and a dose of luck:

- Plugs: NGK PFR5G-11 (Standard), not the colder ones (6G or 7G)- OEM Air Filter & Fuel Filters; both replaced approximately 5k miles ago- Mobil1 10W30- 93 Octane, Amoco (almost exclusively)- Redline Fuel System Cleaner (added one bottle to a full tank three days ago; still 1/4 of tank left). I try to run a bottle once every 90 days.- Throttle Body thoroughly cleaned three weeks ago (had to remove it completely while replacing the VC gaskets)

SIDE NOTE: I had read that doing the VC gaskets on the driver side was painful....I found out that doing it on an Active, is even worse, because of the hydraulic lines going to the actuators... . And the passenger side is not easier; the combination of this line and the AC pipes feeding to the evaporator, close to the firewall, make it almost imposible to put back the VC without knocking the gasket out of place. I had to reposition the gaskets three times, until I got it right. So far, no leaks!

- EGR & PCV Valves also thoroughly cleaned- Still need to clean the Plenum - I cleaned as much as I could when I had the TB off.- Same applies to the IAC- Fresh Coolant (replaced two weeks ago)- Thermostat fully operational (Temp gauge points between 3:00 and 4:00 o'clock)- O2 Sensors - original - KS - original; one is Open, the other is ok, although sometimes the resistance readings vary. As a temporary "fix" I am running them both with 560kOhm resistors, one each, in parallel with the KS... Don't flame me...I plan on replacing them as soon as I have some extra $$$....- Injector (resistance measured through harness) - Min: 12.3, Max: 13.0 Ohms- Never cleaned the MAF sensor. I don't mess up with it either - oil filter changes done from underneath the car so not to put any stress on the electrical connector or the air duct/MAF housing.

On my daily commute I go up and down a few hills and I try to downshift to 3rd or 2nd and push the RPM to the 3k to 4k range for a few minutes, traffic and cops permitting... Also use engine brake/compression when going downhill...and avoid OD/4th in traffic under 50 MPH

[maxnix]

Mike,I don't have one good tip, but these are some of the things I do/use or have recently done. It may be a combination of things, and a dose of luck:

- Plugs: NGK PFR5G-11 (Standard), not the colder ones (6G or 7G)- OEM Air Filter & Fuel Filters; both replaced approximately 5k miles ago- Mobil1 10W30- 93 Octane, Amoco (almost exclusively)- Redline Fuel System Cleaner (added one bottle to a full tank three days ago; still 1/4 of tank left). I try to run a bottle once every 90 days.- Throttle Body thoroughly cleaned three weeks ago (had to remove it completely while replacing the VC gaskets)

SIDE NOTE: I had read that doing the VC gaskets on the driver side was painful....I found out that doing it on an Active, is even worse, because of the hydraulic lines going to the actuators... . And the passenger side is not easier; the combination of this line and the AC pipes feeding to the evaporator, close to the firewall, make it almost imposible to put back the VC without knocking the gasket out of place. I had to reposition the gaskets three times, until I got it right. So far, no leaks!

- EGR & PCV Valves also thoroughly cleaned- Still need to clean the Plenum - I cleaned as much as I could when I had the TB off.- Same applies to the IAC- Fresh Coolant (replaced two weeks ago)- Thermostat fully operational (Temp gauge points between 3:00 and 4:00 o'clock)- O2 Sensors - original - KS - original; one is Open, the other is ok, although sometimes the resistance readings vary. As a temporary "fix" I am running them both with 560kOhm resistors, one each, in parallel with the KS... Don't flame me...I plan on replacing them as soon as I have some extra $$$....- Injector (resistance measured through harness) - Min: 12.3, Max: 13.0 Ohms- Never cleaned the MAF sensor. I don't mess up with it either - oil filter changes done from underneath the car so not to put any stress on the electrical connector or the air duct/MAF housing.

On my daily commute I go up and down a few hills and I try to downshift to 3rd or 2nd and push the RPM to the 3k to 4k range for a few minutes, traffic and cops permitting... Also use engine brake/compression when going downhill...and avoid OD/4th in traffic under 50 MPH

MintQ45a (is it IPQ?), you are correct to use the 5 heat range in SEA.

Traffic being what it is in SEA (unbearable), try WOT runs on on ramps holding to redline.

Your gear use is to be commended in that you avoid lugging engine below 2,500 rpm.

BG44K is the best injector clenaer also. Replace fuel and air filters annually.

[goody90q45]

Mike- replacing your t-stat will help (i know you said it had gone missing)........must get engine/cats nice and hot to keep the HC down.

I did not have a thermostat installed when I took the smog test in July (didn't know it at the time) and I purposely brought it in straight from home (3 miles) on a coolish morning so it wouldn't be completely warmed up. Oops.

My gas mileage is down the last couple of tanks from 15+mpg (100% surface streets) to barely 14mpg. I wonder if it has anything to do with the (mandated) switch from summer gas to winter gas? Even though I've replaced them I can't help but think that it's an O2 sensor since I remember Jared (or was it Andy, sorry guys) pointing out on Nissan Data Scan (NDS) how they should fluctuate wildly between 0 and 100. My scan shows them moving full scale but very slowly.

I need to get in touch with Jared and Andy to hook up our NDS and compare O2 sensors. What do you say guys. A pre-Christmas Meet at your place or mine? We'll get a picture to post here of the 3 of us engineers holding laptops standing by our Q's. Bring your pocket protectors and horn-rimmed glasses.

[goody90q45]

Mike,I don't have one good tip, but these are some of the things I do/use or have recently done. It may be a combination of things, and a dose of luck..

I've done a lot of the same things you listed since I bought my Q 2 1/2 years ago. Not all, but most.

Based on your test results I'd guess your Q is running very strong. My Q runs great but by California standards I'm one smog test failure away, because of the car's age, from being permanently labeled a "gross polluter" and having to go on a yearly smog check cycle instead of every 2 years.

I'm also concerned about the wasted fuel at $3.50 a gallon. The 1mpg drop in fuel economy (5%-6%) that shows up as a failed smog test is a lot of money out of the pocketbook. The smog check in any state, even though it's expensive and tedious, forces the owner to maintain their engine in very good condition.