tmak26b

Hey guys, i have a 90 NA with 152K miles. I bought it last year with 76K miles. I've changed the plugs 3 or 4 times since I owned the car, everytime I would get plugs that have that tanish look. Since the first time I changed my plugs, I have gutted my cats and changed to a higher flow muffler, but the result is the same thing. The plugs would still look tan, so I am thinking that I am running on the lean side, is there a way for me to turn up the mixture just a little to get more fuel in? Also help me gaina few hp... Thanks

Felix Wankel

86-88 cars had a rich/lean screw on the passenger fenderwell, near the airbox. I don't know about the 89-91 cars though.

MaxRX7

cymfc3s

You try running a higher octane gas? Richening up the mixture wont give you more HP, its the other way around.

Boosting_FC

Try changing the fuel filter yet? Other than doing the maintainance stuffs, remapping the ECU ROM or S-AFC is another method. I don't think there is a cheaper way for our S5 cars. Jay