So i went to clean out my air filter, throttle body and change the plugs hoping to get ride of some bad idle problems....i put eveything back together and i noticed i went from a 11.9 AFR at WOT before, to a 10.0 AFR afterwards and worse gas mileage.....so i changed the plugs back and still have a screwed up AFR....i dont' know how that could happen...do i have a vacuum leak or throttle body leak or something....Any suggestions would be great....And When spraying 50/50 Meth does it make your AFR Leaner or Richer??

 

Well having a 11.9 AFR is pretty lean to begin with... but 10 is pretty rich.

I would think that spraying methanol would make your AFR appear leaner... but I am not sure about that.

 

Spraying water methanol (methanol being a fuel) will make your A/F go richer. You can expect a 50/50 shot to richen your air fuel by .7-1.0 full point.

 

Did you re-oil the filter,Im guessing your running a cai if you got meth injection,To much oil might be restricting the filter some what or the filter is plugged up worse after cleaning it .
Just a thought.

 

i removed all the oil from the filter and left it dry and still runs like crap.... could it be a MAF senor problem, needing to be reset ot something, does the MAF control the Throttle Body??