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Help ! bolt on ls1 throwing codes P0300; P0171

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Old Oct 14, 2015 | 07:37 AM
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Default Help ! bolt on ls1 throwing codes P0300; P0171

bolt on, dyno tuned ls1 SS Camaro throwing P0300 and P0171.

you can feel it randomly miss, then it will be fine. 2 weeks ago installed the MSD 8733 2 step. checked all the plugs/wires they feel tight.

sprayed brake clean around to check for vacuum leak.

is it possible a bad 02 sensor ? there is no 02 sensor codes though

the car is tuned to read 02s and allow CEL to come on (hence how I know I have codes)

if it was narrowing it down to a cylinder I wouldn't need help but at a loss currently. was supposed to run bracket tonight but cant unless I figure this out in the next 8 hrs !

thanks-
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Old Oct 14, 2015 | 03:35 PM
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Seems pretty clear you have at least one cylinder misfiring - you are getting the P0300 misfire code and can even feel/hear it.
When a cylinder misfires, unused oxygen goes out the exhaust causing the O2 sensor to report an excessively lean condition. I don't there is anything wrong with your O2 sensors.

Have you tried removing the MSD 2-step?
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Old Oct 14, 2015 | 04:03 PM
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Originally Posted by mrvedit
Seems pretty clear you have at least one cylinder misfiring - you are getting the P0300 misfire code and can even feel/hear it.
When a cylinder misfires, unused oxygen goes out the exhaust causing the O2 sensor to report an excessively lean condition. I don't there is anything wrong with your O2 sensors.

Have you tried removing the MSD 2-step?
thanks for the reply !
so in between jobs today at the shop pulled some plugs and you can clearly see that bank 1 is having an issue and bank 2 is running fine. I disconnected the msd 2-step and reset the computer will drive cycle to see what the result is.

I sent my tuner live data readouts from my snap on scanner and he said to not rule out the 02 sensor being bad especially since it is spliced and extended.
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Old Oct 14, 2015 | 04:19 PM
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In the tool you should be able to disable fule trims if the lean condition is causing the misfire then that should clear it up as the o2 won't have any control. Usually though the misfire makes the car see lean on the o2.
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Old Oct 14, 2015 | 05:46 PM
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Originally Posted by 98redorangeta
In the tool you should be able to disable fule trims if the lean condition is causing the misfire then that should clear it up as the o2 won't have any control. Usually though the misfire makes the car see lean on the o2.
it looked like my tuner had them disabled already but still showed misfire.

I unplugged the 2-step, cleared the codes, drove the car, so far 2 pendings on o2 sensor bank 1 sensor 1 for slow switching and response. So it looks like the o2 sensor is the culprite here... going to get new sensor and extenders from ws6 store and see. Meanwhile it is still possible that my 2-step is defective causing other issues...
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Old Oct 15, 2015 | 10:39 AM
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Ordered the 2 o2 sensor extenders, going to put new delco sensors in.
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Old Oct 18, 2015 | 10:19 AM
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new sensors with extenders still getting slow response and insufficent switching.
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Old Oct 18, 2015 | 05:58 PM
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Does the car still have a misfire? The codes with long tubes aren't that surprising.
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Old Oct 18, 2015 | 09:08 PM
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as of right now I did not get another misfire or lean code

I need to drive it more though and it did not feel like it was missing today.

I think that the old o2 took a **** and caused bank 1 to lean and caused misfire.

because even if it has slow response/ insufficient switching but the sensor is good I think I should be fine...
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Old Oct 18, 2015 | 10:17 PM
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If you lightly hold the throttle, does the sensor wake up? If so, you could go to the closed loop proportional idle air flow table under fuel-closed loop. Multiply all values by 1.10. Will wake up the O2 at idle.
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Old Oct 20, 2015 | 06:29 PM
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watching the constant data now they both are awake and equal even at idle
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Old Nov 3, 2015 | 03:04 PM
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have you changed your switchpoints to match the longtubes? You've moved the sensors farther away from their stock location so they aren't going to read correctly.
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Old Nov 3, 2015 | 05:31 PM
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Originally Posted by CamaroSS22
have you changed your switchpoints to match the longtubes? You've moved the sensors farther away from their stock location so they aren't going to read correctly.
yes my tuner did that
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