Engine Ran my code reader and

[Mindseye007]

Just did my oil change 5w30 Mobil 1 fully Synthetic Extended milage with the Motorcraft FL1 OIL filter and My car is running like a dream so smooth and is getting better gas milage since I added a new Egr valve So I took her out for a drive yesterday there was no CEL but when I got back I decided to check for codes anyway.

KOEO : 41 91 95 85 15
KOER : 21 94 44
I also have a svt chip installed for code 15 and 2 brand new Motorcraft oxygen sensors. Let me know you thoughts on the other codes maybe some things are turned off in the tune for 94 Octane.

 

[89ripper]

Well 41/91 are system running lean..you replaced oxygen sensors and you said it ran fine, so maybe just need to reset and clear codes. You have some smog codes as well from doing a search on here you can find jrichker posts on how to do some of the testing for those. Its a little over my hesd but thats how I cleared up my problems. I used to get 41 and 91 turned out to be the wiring, but my car was running like crap

 

[Mustang5L5]

The KOEO codes may be history codes. You may want to erase the codes, do a couple drive cycles and then pull them again to see if they are current.

 

[Mindseye007]

The KOEO codes mate be history codes. You may want to erase the codes, doa couple drive cycles and then pull them again to see if they are current.

OK, I will do that thanks Mustang5L5.