The location of #6 is on the front bank, those are the even cylinders 2-4-6-8. The way GM has done it, and I believe it continues this way, Is bank 1 usually refers to the bank with cylinder #1, and bank 2 with #2. And I believe it is still odd on one bank, and even on the other.
If it were my money to spend, and the check engine light was currently not on, I would wait till it comes on and go from there. It sounds like the running is not that bad. It is possible that internal circuitry in the module is causing the p0306 without there being a misfire. Did you swap the coils by chance, if the p0306 comes back, I would swap the coils, clear the codes, drive it until it comes back. If it comes back with a p0305, then replace the silver coil and return them to there original locations.
As far as the smell, I would not replace the converter. The only time I would recommend replacement of a converter on a vehicle with catalyst monitoring(like yours) is when the check engine light comes on. Here is some info on the sulphur issue, one bulletin is rather old, and one is new, but they both say about the same.
#31-66-02: EXHAUST ODOR AND OTHER FUEL RELATED CONCERNS - (Nov 18, 1993)
"GM OF CANADA" AND "NAES" DEALERS ARE NOT AUTHORIZED TO UTILIZE THIS SERVICE BULLETIN.
SUBJECT: EXHAUST ODOR AND OTHER FUEL RELATED CONCERNS (USE KNOWN GOOD QUALITY FUEL)
MODELS: 1990-1993 CADILLAC DEVILLE, FLEETWOOD, SIXTY SPECIAL (FWD) 1990-1993 CADILLAC ALLANTE 1990-1994 CADILLAC ELDORADO, SEVILLE 1994 CADILLAC DEVILLE, DEVILLE CONCOURS (WITH 4.5L, 4.6L OR 4.9L ENGINES)
SOME 1990-1994 VEHICLES THAT REQUIRE PREMIUM FUEL USAGE MAY EXPERIENCE ONE OR MORE OF THE FOLLOWING INTERMITTENT DRIVEABILITY CONDITIONS:
O EXHAUST ROTTEN EGG ODOR OR SULFUR ODOR. O POOR COLD ENGINE OPERATION: NO START/HARD START, START/STALL AT IDLE. O HOT RESTART PROBLEMS. O ROUGH/MISS AT IDLE. O HESITATION AND/OR LACK OF POWER. O DETONATION.
THESE CONDITIONS MAY OCCUR DUE TO THE FUEL IN THE VEHICLE. POOR FUEL QUALITY HAS BEEN RECOGNIZED TO CAUSE ANY OF THE CONDITIONS LISTED ABOVE. HIGH SULFUR CONTENT FUEL HAS BEEN RECOGNIZED TO CAUSE EXHAUST ROTTEN EGG ODOR OR SULFUR ODOR CONDITIONS. OXYGENATED FUELS WHICH ARE USED IN MANY AREAS OF THE COUNTRY MAY HAVE A DISTINCTIVE ODOR. THIS IS CONSIDERED NORMAL, AND IS NOT RELATED TO THE EXHAUST "ROTTEN EGG" ODOR.
THE OBJECTIVE OF OXYGENATED FUELS IS TO REDUCE TAIL PIPE EMISSIONS OF CARBON MONOXIDE. CARBON MONOXIDE IN THE ATMOSPHERE, ESPECIALLY DURING WINTER MONTHS WHEN IT IS AT ITS HIGHEST LEVELS, CAN AFFECT THE HEALTH OF PEOPLE WITH HEART DISEASE AND RESPIRATORY PROBLEMS. THE OXYGENATED FUELS CONTAIN OXYGEN COMPOUNDS THAT MAKE COMBUSTION MORE EFFICIENT WHILE LOWERING CARBON MONOXIDE LEVELS IN THE ATOMSPHERE.
THE FEDERAL CLEAN AIR ACT AMENDMENT OF 1990 REQUIRES THE USE OF OXYGENATED FUEL IN NEARLY ALL CARBON MONOXIDE NON-ATTAINMENT AREAS IN THE UNITED STATES. THE PROGRAM BEGAN LAST WINTER IN CERTAIN NON-ATTAINMENT AREAS. THESE REGULATIONS WILL CONTINUE IN FUTURE YEARS WITH WINTERTIME FUEL STARTING, IN SOME CASES, AS EARLY AS THE BEGINNING OF SEPTEMBER AND ENDING AS LATE AS APRIL DEPENDING UPON THE AREA OF THE COUNTRY.
#09-06-05-001: Information on Sulfur Odor from Exhaust - (Jan 30, 2009)
Subject: Information on Sulfur Odor from Exhaust
Models: 2007-2010 GM Passenger Cars and Light Duty Trucks (Including Saturn)
2007-2010 HUMMER H2, H3
2007-2010 Saab 9-7X
with Gasoline-Powered Engines
Important: This bulletin is not applicable to vehicles operating in Canada on Canadian sourced fuels. Canadian regulations limit the amount of sulfur in gasoline to 80 PPM or less for all gasoline marketed in Canada with no exemptions.
Federal regulations limit the amount of sulfur in gasoline to 80 PPM (some states have lower limits; for example, California's limit is 30 PPM). The federal exception to this rule is an allowance for qualifying small refineries that permits up to 450 PPM until January 1, 2011. Sulfur odor in exhaust from vehicles equipped with gasoline engines is caused by excess sulfur in the gasoline and it cannot be eliminated unless the source of the sulfur is eliminated.
Important : Replacement of catalytic converters for this condition is not an appropriate repair and will not correct the condition by itself.
Don't Do This
Change brands of gasoline.
DO NOT replace the catalytic converter.
Customers with vehicles that exhibit this condition should be advised of the information in this bulletin and be asked to switch the brand of gasoline that they are using. In most cases, this will result in elimination of the sulfur odor by the time one tank full of gasoline is consumed if the gasoline that was added is within the 80 PPM federal limit.
In order for the odor to be eliminated. Two things must occur. First, the gasoline added to the vehicle must be at or below the federal 80 PPM limit. Secondly, the vehicle must have run long enough to have consumed one tank of fuel containing a sulfur content of 80 PPM or less.
Although there is no way for a dealership to easily measure the amount of sulfur in gasoline, it's a good practice when asked for a recommended brand of gasoline to recommend any of the Top Tier Detergent Gasoline Brands. Although Top Tier brands have not demonstrated that they contain a lower sulfur content than other brands, their detergent additive package makes them a preferred choice when choosing a brand of gasoline for your vehicle. A complete list of Top Tier Brands can be found in Corporate Bulletin Number 04-06-04-047H (in Canada, refer to Corporate Bulletin Number 05-06-04- 022E) or by accessing the website www. Toptiergas. Com.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
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Wednesday, January 20th, 2010 AT 10:37 PM