mt82#1fan
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Went to my first track day and had a blast - it was the perfect opportunity to begin to find the limits of the s550 platform. The car performed admirably! The first thing I ran into was a flickering CEL after a very hard braking zone - it didn't recur in that session but became a solid CEL in the next session.
Got back to the paddock and pulled the code, P0300 Random misfire. Wasn't able to clear the code with the SCT tuner device so I went home to investigate further. After researching a ton on here I determined it was related to intake, spark or fuel. After inspecting the intake I noticed that the clamp on the rubber intake elbow going to the airbox was somewhat loose and if I flexed it forward it would come apart enough for unmetered air (air having not passed the MAF) to get in. This made sense to me because under heavy braking presumably the engine is lurching forward and compressing this area allowing for air to get in and cause the engine to run misfire / run lean presumably.
The other code my ProCal pulled was P061A which I thought was weird because I am completely stock power train wise. After speaking with Ford Performance they mentioned this code is typically for the ECU having the wrong tire size or an intake vacuum leak somewhere. Since I had just cinched down every connection and even zip tied some for extra insurance it had to be the tire size.
I used the diagnostic function in ProCal to adjust the tire size from 738 to 754 for 275/40/19 Michelin Pilot Sport 4 All seasons on the advice of FP. All good now! Just posting this in case someone else runs into a similar issue.
Got back to the paddock and pulled the code, P0300 Random misfire. Wasn't able to clear the code with the SCT tuner device so I went home to investigate further. After researching a ton on here I determined it was related to intake, spark or fuel. After inspecting the intake I noticed that the clamp on the rubber intake elbow going to the airbox was somewhat loose and if I flexed it forward it would come apart enough for unmetered air (air having not passed the MAF) to get in. This made sense to me because under heavy braking presumably the engine is lurching forward and compressing this area allowing for air to get in and cause the engine to run misfire / run lean presumably.
The other code my ProCal pulled was P061A which I thought was weird because I am completely stock power train wise. After speaking with Ford Performance they mentioned this code is typically for the ECU having the wrong tire size or an intake vacuum leak somewhere. Since I had just cinched down every connection and even zip tied some for extra insurance it had to be the tire size.
I used the diagnostic function in ProCal to adjust the tire size from 738 to 754 for 275/40/19 Michelin Pilot Sport 4 All seasons on the advice of FP. All good now! Just posting this in case someone else runs into a similar issue.
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