2017 Mustang with Roush Stg 1 Misfires and OL Fault

[JekylHyde]

Buddy decided to have a shop cut out his cats and also swap out clutch now its going into a OL Fault status and giving cylinder 4&7 Misfire codes. Car was running perfectly for months and now its doing this. . Plugs are brand new as well. rear O2s are in exhaust and electrical is still plugged in. Attached is log and Tune.

OG11.hpt OL Fault.hpl

[SultanHassanMasTuning]

did you do a crank relearn? after the clutch

[JekylHyde]

did you do a crank relearn? after the clutch

No sir. I would assume the shop that did the swap did it. Car drives perfectly and then will randomly do the misfire on the logs.

[17GT]

Does he have headers with o2 extender harnesses? They can cause intermittent faults like this. The DTC code for heater resistance is turned off and what I have seen happen when the extender harnesses get heated a bunch by the headers. This will cause shorts that will make the heater not work intermittently. One side seems to swing more than the other much richer or leaner so you may have a o2 heater intermittently not working and you can't see it because the mil light is turned off. Turn that on for bank 1 and 2 sensors 1 and log o2 heater faults if he has extender harnesses. Bank 1 seems to be swinging different from bank 2 so that would be one to look at I think. (Bank 1 is passenger side Bank 2 drivers side unlike an LS).

[JekylHyde]

did you do a crank relearn? after the clutch

They got back with me and said they didn't do the relearn. Performed it and worked first try. You're the man thanks!

[17GT]

They got back with me and said they didn't do the relearn. Performed it and worked first try. You're the man thanks!

Still have him turn those o2 heater codes back on for the front o2's. Will keep em from chasing his tail if he ends up having a fault.