i have an 89 daytona shelby z with a 2.5 garrett. a 2.5" downpipe with 3" to the muffler other wise it is stock. i am having an issue with it misifiring. but it is only sometimes. but when it is missing it is constant (duhduhduhduhduhduhduhduhduhduh) instead of (mmmmmmmmmmmmmmmmmmmmmmmmm) lol it only does it when there is a load on the engine (has happened a wee bit at idle too) i can figure out what it might be also pops alot on decel. the ohms on the wires were checked all good they are for sure in the cap i have codes 12,31,45 but none of those are relavant. the timing is set at 12. the spark plugs are good, i had my wideband out but i decided to put back in last night and the numbers confused me. if i start it it will sit at about 12.6 (choke on per say) cause its damn cold up here! then it slowly goes up till it runs off the top of the gauge and idles between 16.8-18+ but sometimnes ideles at 14.2?? then driving it stays up in the 16-18 range and at wot its 10.6......... but thats when its not missing when it was missing the numbers are the same except if i floor it it will hit 11.6 and creep towards 12 then 13?!?!?!?!!? i dont undeestand!! one minute it will run good next like a tractor!!!