here just a quick one...i searched but everthing came up to vague... where are the plugs/plug to check for codes on a 91 n/a fc...also is it the same connectors as fords?

 

if it's like the S4's, it's a 6-pin green connector next to the leading ignitor/coil pack. A quick search will yeild pinouts and instructions on how to make a two led code checker.

 

It has been awhile for me but I have an 89 FC and it is a single plug, green I beleive, between the battery and the drivers side fender. Take a wire and ground it to the neg. battery terminal . Then get in the car and turn the key to ON but do not start the car and watch the check engine light blink, short blinks represent 1 and longer blinks represent 10. IF there is more than one diagnostic code there will be a pause and it will send another code. Lowest numbered codes are sent first.

 

well heres one...if i get no check engine lightwhile the car is running ...should i bother making one? and take a wire from where... the battery is grounded..lol, wut wire where?