traceface1086
New Member
2010 Expedition. First had a code for #4 coil. Changed all coils and plugs. Code went away but p0021 appeared along with a rough idle. Has progressively gotten worse and now idles rough, shakes and struggles uphill and jerks at higher rpm. Changed oil and filter, new VVTs on both sides, also swapped CAM sensors and code remained bank 2 (p0021). What else can I check? I'm lost. I have a diagnostic tool . spark adv is all over the place (jumps from 12 to 16 to 24 back to 16) but idk what that means or how to read the other numbers..