i installed a spectre air filter in my 2003 3.0 flex ranger a day later the CEL light started flashing now its on constant code is misfire cylinder # 4 could it be the flex motor does not like the added air flow

 

Highly doubtful. Probably just a coincidence. Our local Kmart/Sears stocks Spectra brand air filters, and I have replaced my OEM with one. When was the last time you had a tune-up? That would probably be a much needed service.

 

thats my next thing to do need to wait till the first of the month when i have some extra cash just bought this ranger it has 116k did oil change and air filter will do fuel filter plugs and wires

 

Sounds good. It is probably due for a tune-up if the vehicle has 116K miles. Welcome!

 

update i ran some STP gas treatment no CEL this morning went for about a 2 hour drive no worry's still needs a tune up and a set of shocks