[rambostang]

Hello all!! I'm a newbie to this site and I have a question about rich/lean fuel readings. I have an '98 gt with powerdyne super charger-24lb injectors,90mm mass air and larger fuel pump. I have more mods but these are my motor ones. I purchased her used with all these on it and a 3 pod guage cluster with a fuel mixture. I just replaced the cat back system from borla to new magna flow (I've had them on my last '97 gt but stock motor and loved the deep sound). First the check endine light came on and it was running a little rough. So I disconnected battery to "reset" my settings. Since then she runs great and no light but I have noticed that she runs leaner. I the guage that has 5 l.e.d.s for lean(red) 5 for yellow and 5 for rich. Before I would see all red and 3 to 5 yellow when I really got into her. Now its all red and MAYBE one or two yellow at times. I'm worried I'm running too lean. Any suggestions would help. My previous stangs were all stock except for CAI,K/n,mufflers,h-pipe but I couldnt turn this one down. I dont have much experience with fine tuning and my cars are driven for pleasure.

[markwondi]

First off, those 24lb injectors aren't helping. And secondly, a catback on a blown setup will play with your closed loop A/F. You need a tune and larger injectors.

[rambostang]

I m stupid but what does "tune" involve??

[BlueStreak03]

It involves strapping your car down to a chassis dyno and monitoring the A/F ratio while the car is at wide open throttle. Once the run is over, the guy who's writing the tune will take the data and adjust fuel curves, fuel trims and ignition tables to optimize fuel and spark delivery while making sure that no pre-detonation is happening since this will end the life of that motor with a quickness.

[rambostang]

thank you, i appreciate it