renips

P0131
P0161
300 random misfire
1151 I think this is the insufficient switching?

Anyway.The care has 156K on the odometer. It is a weekend car. I just changed spark plugs. Car had an LS1 edit tune a few years back. It seems to run good

I have noticed that the car when parked and running that the exhaust is emitting black soot or I guess carbon on the ground. When the plugs were changed one side was very dark the other not so.

One of the codes is indicating insufficient switching. It seems to be running OK. The reason I had the plugs changed was because i did notice some sluggish and some misfire. After some time does the car need a tune again? I know as miles increase maybe the engine needs to be retuned. Any help would be appreciated

CAMSTER

iTrader: (10)

Check your spark plug wires, and you may want to check all your coils, the correct way, not by disconnecting the wires, cause this will mess up the coils, get the inline lamp, used for this purpose, be sure you are using the factory specified spark plugs. Put a bit of fuel injector cleaner in your fuel, like twice the recommended amount to a tank full... Check the catalytic converters.

renips

I am using the factory plugs. Could you explain what the inline lamp is and how it is done? What would indicate a bad coil? I am using the fuel injector cleaner now. I have long tube headers and kooks y pipe along with GMMG exhaust for reference. I notice you are also in Florida..

Thanks