Buick Regal 3800 Series I V6 emissions test coming up

[trinacriabob]

Ok, I have the Regal with the 3800 V6 Series I 1992 that now has original mileage in the high 200,000s. Incidentally, they have no EGR valves.

I will soon have to go get its emissions test to renew the tags.

Here's the deal. In most states that I've lived in and in which the car has been registered, they test 4 emissions components (HC, CO, CO2 and O2). In California, they add NO (nitrogen or nitrous?).

At any rate, the car has performed fantastically on the first 4 components...extremely clean and changed minimally over the years. However, it's not as clean on the N.O., though it has always passed. I heard that this is common: cars run clean on all the others and a little dirtier, or closer to the limit, in the N.O. department.

It's been 2 years and I'm wondering how it will go. What I've heard/read is:

1 - you can tweak the timing...but these cars don't take timing adjustments, everything is sealed, and I'm not a techy

2 - run a bottle of fuel injector cleaner of a good brand (Techron) in the tank before or during its test

3 - consider bumping up from low-grade to mid-grade unleaded

Any ideas on whether this is fact or fiction? If it's true, what's the logic behind this recommendation? Any help is appreciated.

[SAmadei]

Ok, I have the Regal with the 3800 V6 Series I 1992 that now has original mileage in the high 200,000s. Incidentally, they have no EGR valves.

I will soon have to go get its emissions test to renew the tags.

Here's the deal. In most states that I've lived in and in which the car has been registered, they test 4 emissions components (HC, CO, CO2 and O2). In California, they add NO (nitrogen or nitrous?).

At any rate, the car has performed fantastically on the first 4 components...extremely clean and changed minimally over the years. However, it's not as clean on the N.O., though it has always passed. I heard that this is common: cars run clean on all the others and a little dirtier, or closer to the limit, in the N.O. department.

It's been 2 years and I'm wondering how it will go. What I've heard/read is:

1 - you can tweak the timing...but these cars don't take timing adjustments, everything is sealed, and I'm not a techy

2 - run a bottle of fuel injector cleaner of a good brand (Techron) in the tank before or during its test

3 - consider bumping up from low-grade to mid-grade unleaded

Any ideas on whether this is fact or fiction? If it's true, what's the logic behind this recommendation? Any help is appreciated.

In NJ, you can fail for HC, CO or NOx... typically, NOx is produced from a hot combustion... lean combustion or EGR problems. No EGR, which would be the first think I'd check means that I would likely run the car through with some fuel injector cleaener and try to keep the engine temp down when you take it through. I'll usually pick a nice, cool day and visit something near the inspection station... so the car can cool down and not leave the car idle in line.

I would also consider replacing the O2 sensor, as it controls your mixture, and could be causing a lean condition.

If your HC and CO are good, I might consider a new thermostat... possibly one that opens a bit lower. But I'd only do that if it failed. I suppose a clogging catalytic could also raise the combustion temperatures.

Weather conditions have a lot to do with how the emissions work... especially in a borderline car. I've taken the same car through on different days and passed when it failed a few days before... and I hadn't changed a thing. Luckily, in NJ inspection is free at the state inspection centers and you can go though as many times as needed.

I like the new OBD-II stuff... in NJ... no sniffer/treadmill... they just trust the computers tests... so as long as you don't have a CEL, you likely don't have an emissions problem.

[trinacriabob]

In NJ, you can fail for HC, CO or NOx... typically, NOx is produced from a hot combustion... lean combustion or EGR problems. No EGR, which would be the first think I'd check means that I would likely run the car through with some fuel injector cleaener and try to keep the engine temp down when you take it through. I'll usually pick a nice, cool day and visit something near the inspection station... so the car can cool down and not leave the car idle in line.

I would also consider replacing the O2 sensor, as it controls your mixture, and could be causing a lean condition.

If your HC and CO are good, I might consider a new thermostat... possibly one that opens a bit lower. But I'd only do that if it failed. I suppose a clogging catalytic could also raise the combustion temperatures.

Weather conditions have a lot to do with how the emissions work... especially in a borderline car. I've taken the same car through on different days and passed when it failed a few days before... and I hadn't changed a thing. Luckily, in NJ inspection is free at the state inspection centers and you can go though as many times as needed.

I like the new OBD-II stuff... in NJ... no sniffer/treadmill... they just trust the computers tests... so as long as you don't have a CEL, you likely don't have an emissions problem.

Thanks for the advice!

A couple of things:

- it never really ran hot, but since I put in a new radiator last year, it runs REALLY cool...maybe that will be good

- since I'm not getting any lights, I'm going to try to hold off on the O2 sensor

- wow...so the high NJ taxes get some free perks...here, the inspections are at private places that are state approved

A few questions:

- I had an O2 sensor done about 50,000 miles ago...do you believe in routinely changing these even without the OBD amber signal?

- should you run the F.I. cleaner in the tank BEFORE the inspection or DURING the inspection? Together with 89, instead of 87, octane?

Thanks!

[regfootball]

move to north dakota......LOL

i would run complete fuel system cleaner through the car for a couple tanks prior to the test and then run premium for the test. Not scientific belief on my part but it may get some carbon out of your engine.

at this point most 5 and under year old cars are so clean i don't see why make cars like yours jump through hoops to remain on the road.

[SAmadei]

- it never really ran hot, but since I put in a new radiator last year, it runs REALLY cool...maybe that will be good

Hopefully that will help make the difference.

- since I'm not getting any lights, I'm going to try to hold off on the O2 sensor

- I had an O2 sensor done about 50,000 miles ago...do you believe in routinely changing these even without the OBD amber signal?

The O2 sensor tends to wear out slowy the and CEL only comes on if it REALLY out of wack. I replaced mine after 100K and it was looking pretty bad... but no lights... the car ran noticeably better afterwards. I would probably leave the 50K O2 sensor alone, for now. If you have some high temp antiseize, you could inspect it... but be careful.

- wow...so the high NJ taxes get some free perks...here, the inspections are at private places that are state approved

Hardly a perk... I have almost come to blows at these stations. They don't understand cars, refuse to follow procedure, and are very inconsistant. I've been lucky for the last couple trips through... but I know it can't last.

A few questions:

- should you run the F.I. cleaner in the tank BEFORE the inspection or DURING the inspection? Together with 89, instead of 87, octane?

It depends on how scared you are that its going to be a problem. I would likely just run a potent can of FI injector cleaner before the test. I worry that some of the cleaners could screw up emissions.

I wouldn't worry about the gas... the better gas has more detergent and/or better quality control, so it likely would have kept things cleaner over the long run... but one tank won't make a difference. If you had a preignition problem, I'd definitely use the higher octane stuff... but you have a knock sensor, so the car can react and maximize the ignition for the fuel... so I don't think 87 vs 89 will make a difference. Historically, GM tells owners to your the lowest octane fuel recommended by the owners manual... only use higher if knocking is an issue. Otherwise, its a waste of money.

Thanks!

Anytime.

at this point most 5 and under year old cars are so clean i don't see why make cars like yours jump through hoops to remain on the road.

I agree. We already have laws that visible smoke will get you a ticket... and the people in the middle of the spectrum between clean and smoky just run their junk through crooked mechanics.

Most people at this point have a newer car... and if the emissions go out of wack, the CEL goes on, they panic, bring it to the mechanic (or trade it in IMMEDIATELY!).

[vonVeezelsnider]

Thank god there aren't any of those pesky emissions tests and inspections in Alberta, the hassle of it would really honk me off living elsewhere especially when you get used to not having to deal with it.

[trinacriabob]

Thank god there aren't any of those pesky emissions tests and inspections in Alberta, the hassle of it would really honk me off living elsewhere especially when you get used to not having to deal with it.

I'm thinking it's because your population is largely concentrated in Calgary and Edmonton, and that the whole province numbers 3 to 4 million (w/o looking it up). Even then, Calgary and Edmonton feel fairly "spacious." I wonder if they test emissions in Ontario (specifically Toronto).

I'm only torqued about the Nox component. Evidently, a lot of cars run higher in this area. On the other components (seemingly common to all states), it runs super clean. This causes me to shake my head. At any rate, I only see my car going through one more emissions testing cycle as it is nearing 270,000 miles.

[vonVeezelsnider]

I'm thinking it's because your population is largely concentrated in Calgary and Edmonton, and that the whole province numbers 3 to 4 million (w/o looking it up). Even then, Calgary and Edmonton feel fairly "spacious." I wonder if they test emissions in Ontario (specifically Toronto).

I'm only torqued about the Nox component. Evidently, a lot of cars run higher in this area. On the other components (seemingly common to all states), it runs super clean. This causes me to shake my head. At any rate, I only see my car going through one more emissions testing cycle as it is nearing 270,000 miles.

Only BC and Southern Ontario have emissions but in places like Nova Scotia they have a semi-annual safety inspection. We don't even have that unless you are registering the car for the first time in the province.

[balthazar]

FI cleaner raises combustion temps, so I would run it thru BEFORE inspection, not during.

I agree with above: an octane bump is going to do nothing.

[trinacriabob]

Ok, here's the update. I just took the Regal in for its emission test and it passed! I was a little wound up when in the waiting room and looking through the glass. I did not want to go down the diagnostics flowchart with a repair shop.

Just as I expected, it did fine on CO2, O2, H.C., CO...but, again, it came real close on N.O. In fact, it gave roughly the same reading as it did 2 years ago and 7 years ago: a couple of dozen ppm under the low speed max of 772 ppm.

What did I do in the meantime:

( a ) ran a bottle of FI cleaner through it one tank ago,

( b ) got a new air filter, and

( c ) got it tuned, changing its plugs after some 57,000 miles since the last tune-up (they were still clean)

I was expecting a healthier drop in N.O., but it didn't happen. I think that:

( a ) the lack of an EGR valve on this model might make it a little "dirtier," and

( b ) the fact that the cat is the original might not help either

On the plus side, I looked at the values for CO2, O2, H.C., CO particles and those readings are virtually unchanged since its Spring 2003 printout and its Spring 2008 printout. I guess that's good...for having 268.5K miles. Thanks for the suggestions, gents.

Edited March 27, 2010 by trinacriabob