Hi,

Today, from out of no warnings, my car started idling really bad and now it doesn't have much power it also smells like rotten eggs. From what I have read, it almost sounds like the catallactic converter is bad. If so, what is the factory warrany on them and what causes them to go bad?

I just called OnStar and they ran a diagnostic test and it is coding p0300

Thanks

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

P0300 is multiple cylinder random misfire.

Unplug the MAF sensor and see if it runs any different. The rotten egg smell and loss of power is likely caused by the misfiring, unburnt fuel is going through the catylitic convertor and trying to burn off giving a sulfur smell. If the MAF makes no difference, pull the plugs and see how they look, could be time for some new plugs and wires.

Seems like I remember the warranty on the cat being around 80,000 miles or so.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

what if it runs differently without the MAF sensor? also, what is the likelihood of it being the coil packs?

thanks

_________________

05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

Coils could also be the cause, if you have extras, swap them out as well just to see.

If it runs better with the MAF unplugged then it is bad. If it runs worse or the same then it is likely not the issue.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

i did the unplugging and it ran the same :( i read on here where someone tested their coils by spraying a mist of water on them, i wonder will that work.

_________________

05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

I usually pull one plug wire off the coil and start the engine, you should be able to hear / see the spark jumping from the top of the tower to the base of the coil, you can do this at night to make sure you see it if you want. Do one at a time, all six should spark good enough to hear pretty easily.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

thanks, i will give it a try

_________________

05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

Also, the spark from the coil will arc a good distance and loves your fingers. Ask me how I know. XD

_________________
-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

Still the best way to ask a girl to prom.

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

Cats have a 8yr 80K mile warranty. if your getting a stong smell, low power and missfire it is very likely its getting plugged. any mods to the car? cats usually fail from excess fuel.. might have something going on that caused a cat failure. if you have a lazer temp thingy then you might want to start the car and warm it up and read the temps on the inlet of the cat and outlet and see what they read. should be 150*+ higher at the outlet of the cat.

Also if its stock cat then you can unbolt the flange and look to see if the cat is melted.
Good cat: has nice even honeycombs inside


Bad Cat: Broken pieces or melted

_________________
Shane "RedZMonte"
2004 Z16 Z06: Virgin
2000 SSEi: Kenwood DDX512, 3.25" MPS, ZZP DP, PLog, Puck Mount, NGK TR7's, DHP Tuned
1995 Monte Z34: T04e "60" turbo, 42.5# injectors, Borla Catback, OBDII swap, DHP Tuned, Much more...

only mod is cold air intake, car has 67,000 miles on it

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

I tested the coil packs tonight. One pack has no fire at all. One pack has a lot of fire, and one pack has a lot of fire on one wire and not as much on the other. Hopefully, replacing them will correct the problem?

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

replaced the coil pack and still no fire

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

Just to make sure, swap one of your known good ones to that spot. If still no fire, likely the ICM is the problem.

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

i just put the good coil in the bad spot and no fire, and now the no fire coil is firing in the good spot, i guess i will try the icm and hopefully that is it

_________________

05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

1 thing you could have tried before buying a new coil was to swap it with one of the other ones. If it moves with the coil, then the coil is bad. If it doesn't then the ICM is bad. Just my 2 cents.

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'01 Bonneville SLE
'93 Grand Prix SE Coupe 3.4L Twin dual overhead cam

was no big deal, the part's place took it back. hopefully, today, i will try the ICM

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

thanks for everyone's help, i replaced the ICM and she is back up and running!!

thanks again!!

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05 SLE-Other rides: 2010 Buick Lacrosse, 1987 Dodge Dakota, fully restored
November 2010 COTM

Good to hear all is well again

_________________
Ryan

2003 Bonneville SSEi - The Black Mirror SOLD!
2002 Bonneville SE - The Mutt Complete 2004 SLE interior, drivetrain, and body harness swap, ECC swap, HUD swap, black GXP wheels, GXP headlights and tinted tails - SOLD
2003 BMW 540i M Sport, 2001 BMW X5 4.4i, 2010 GMC Acadia, 2017 Grand Design Imagine 3150BH
1982 Cutlass Supreme - The fun one

Just to take that a step further... ALL EMISSIONS RELATED COMPONENTS have a federally mandated 80k warranty. There should be a list in the back of the owner's documents that lists all the components covered by the emissions warranty. Many dealerships will happily charge customers who don't know any better.

Greg