# 2005 Volvo xc 90 T6



## cjm94 (Sep 25, 2011)

Po300 is a random misfire at start up. Could be just worn plugs. Could be fuel bleeding down and low at initial start up... Many things with new plugs clear codes and see if it acts up again


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## mustang64 (Mar 6, 2013)

cjm94 said:


> Po300 is a random misfire at start up. Could be just worn plugs. Could be fuel bleeding down and low at initial start up... Many things with new plugs clear codes and see if it acts up again


Have cleared code. It acted up again and code came back.
What next??


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## Mbjason (Feb 16, 2014)

P0300 is a random miss fire fault code. That can be caused by a lot things, do you have access to the scanner?


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## Mbjason (Feb 16, 2014)

When you say acted up what do you mean?


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## cjm94 (Sep 25, 2011)

A random misfire means the misfire is not lasting long enough to pinpoint which cyl. Meaning it could be just one cyl or multiple cyls. You are going to need a higher end scan tool that can monitor live misfire data and fuel trim data to find this problem. Not a real DIY diagnosis without knowing how to interpret the data it can lead to a lot of parts getting guessed at. Most higher end shops should be able to find the problem within an hours diag time. If it is real intermittent though it could take longer. If it's not acting up sensors will read correctly, but a good tech can interpret learned fuel trim values to lead them closer to the problem area.


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## mustang64 (Mar 6, 2013)

Ok.
Thank you for the information.


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## mustang64 (Mar 6, 2013)

Changed coil on cylinder #5 and cleared the code.
Car is running fine.
Thanks again to all.


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