Da_Droid_Mechanic
Newbie
Anyone know what this is?
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Weird Black Soot in my Exhaust
- Thread starter Da_Droid_Mechanic
- Start date
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Drunkcanuk
I'm Awesome
Usually means your running rich.
Do your eyes burn when it's running and you're down by the pipe?
Check engine light on?
Looks like the inside of an exhaust pipe to me.
MAYBE you should be looking for a failed catalyst. If that's the case, you ALSO need to figure out what killed the catalyst.
MAYBE you should be looking for a failed catalyst. If that's the case, you ALSO need to figure out what killed the catalyst.
Da_Droid_Mechanic
Newbie
No, nothing. It doesn’t even smell it’s so weird!
Da_Droid_Mechanic
Newbie
No, nothing. It doesn’t even smell it’s so weird
Sorry, it’s a 1999 gmc surburban k2500 454! It had a new engine installed a year ago.
Drunkcanuk
I'm Awesome
I'm not sure if you live somewhere where they do emissions testing, but if you do, maybe swing by and they can confirm that's what's happening.
Or don't if they can pull you off the road! Lol
Maybe you have a dead cylinder?
When was the last time plugs were pulled and checked?
Same with the 02 sensor/s?
Or don't if they can pull you off the road! Lol
Maybe you have a dead cylinder?
When was the last time plugs were pulled and checked?
Same with the 02 sensor/s?
454cid
Sooper Pooper
I had black soot coming out the tail pipe of my Volvo 850. It was a faulty O2 sensor. It read low, and the ECM kept dumping fuel into the combustion chambers trying to correct the mixture, and then it would give up and switch to open loop. 02 sensors don't give a steady voltage, they oscillate up and down between 0 and 1 volt. I graphed the output of my sensor and found it wasn't behaving correctly, so I replaced it, and the problem cleared up. I used a Volvo specific App on my phone to do that, but a real OBD scanner, or maybe one of the generic OBD phone apps would work for you too.
If the O2 sensors check out then start looking at other sensor output.
If the O2 sensors check out then start looking at other sensor output.
L31MaxExpress
I'm Awesome
IF you are always into the skinny pedal and hitting power enrichment frequently that will cause soot buildup. On a vehicle that is gasoline powered and not direct injected, I can tell the way it is being driven merely looking at the exhaust. That is assuming no mechanical problems.
That explains why that pipe looked totally normal to me.
On a related note, I don't spend a lot of time looking at other car's tailpipes. Reminds me of dogs sniffing each other's butts.
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