Hi all,

I moved to Tennessee from Connecticut three years ago. There was an emission test in CT and now there is one in TN. I haven't had my brick go through an inspection since moving. I do remember the NOX was on the rather high side last time, though it was good enough to pass. What can I do to reduce NOX and to prepare for the other parts of the emission test (CO and HC)? Anyone heard about a fuel additive product called something like "Guaranteed to Pass"? Thanks, George

If you score a high NOx (and the HC and CO are okay), this usually points to the catalytic converter -- they don't last forever, and my experience (taking three Volvos through NJ's dynomometer testing every two years) has been that a replacement cat will fix up the NOx numbers substantially.
In any case, good luck.

Do you have any stations that sell gasahol (ethanol blend)? It burns cleaner, so should pass easier.
--
1980 245 Canadian B21A with SU carb and M46 trans in Brampton, Ont.

Some bad reps about alcohol blends on Volvo engines (seals and such, for the fuel system, etc.). I'd avoid them.

All gas in Minnesota has 10% ethanol year round by law. Haven't heard of any more problems with seals here than elsewhere. Some say it eats the pickup hose in the gas prepump assembly in the tank.
--
Andy in St. Paul. '89 244 153K mi, '91 745 Regina 202K, '88 244 184K

Besides cars, my boat's owner's (engine) manual instructs owners not to use fuel with more than 5% (I think this is because of the seals in the fuel system); and in addition, it really complicates over-wintering instructions, too ....
With normal gas, I can just fill up the tank (to minimize the air pocket that will collect moisture through condensation) and add fuel stabilizer.
On the other hand, with any alcohol blend, including (I assume 5%), I am supposed to drain the fuel tank (run it to dry? Know where I can dump a hundred gallons or so? :-) and the carbs -- using fuel stabilizer as a treatment instead is NOT an option! I guess this is because alcohol has such a strong affinity for water and therefore more liable to absorb too much water during the year.
Minnesota has always been one of the places I thought I'd like to retire to -- you've got great boating areas -- but how do you boaters cope with this? Is the marine gas (fuel sold at marinas) NOT an alcohol blend?

I wrestled with Ohio emissions this spring with our 91 745Ti. 180K at the time and running great. 74ppm HC (123ppm limit) 1425ppm NO (878ppm limit) so it failed.

Replaced a leaking intercooler hose and added new plugs and failed again.

Bit the bullet and purchased a new cat for $143 and retested. HC 19ppm and NO 18ppm. Sometimes it really does take a new cat to pass.

I think my old cat might have been getting a little stuffed up. The car is much quicker now. I am also getting more turbo whine but the added performance is worth it.

Good luck in your efforts to pass.

Randy

NOX is the killer; you shouldn't have any trouble with CO and HC if the car's running well.
There's a fair amount of evidence that blocking the vacuum line to the ignition box will help NOX considerably.
As always, check for vacuum leaks.

Hi. I could easily be wrong about this, but doesn't that "fix" apply only to earlier systems, in which the vacuum hose went into the control box? I'm not sure if the '86 cars still had that arrangement.