2007 mazdaspeed3 misfire

Dananderson22

Member
:
Mazdaspeed3
Hello I had engine code PO300 come up twice, the first time I cleared it to just see if it was something random and not much of an issue but it appeared again a couple weeks later. A few months earlier the code for a dirty egr valve came up but I haven't gotten around to dealing with it yet. Now more recently after I got the PO300 code I've been noticing that in higher gears/rpms/psi I am experiencing a misfire but still reaching high boost levels (16.5psi). The strange thing about this is that it is random, sometimes when I do a pull there is no misfire at all and other times it is very noticeable. I'm assuming it is either my egr valve is so dirty that the sensor is not reading the valve position correctly or my regapping spark plugs need to be changed. Any thoughts or suggestions? Also, I have a Cobb AP v3 and sf intake, tuned to stage 1 91 + sf. Not sure if it matters. Thank you!
 
I would start by cleaning the EGR since it will cause a misfire and you have a code for it. If the plugs are old you definitely should replace them.
 
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