I had my GSL-SE dynoed today, and it put up some respectable numbers. I can't find the power cord for my scanner so I can't scan it in yet, but it was putting down 125 HP, which was a bit more than I was expecting. But the problem was the Air/Fuel Ratio, my car is running pretty lean.

Now, I'm not exactly sure what the ratio is supposed to be in the SE, but the dyno guys and the fellow rotor heads didn't like what they saw. The AF graph on this dyno is tiny so it's hard to tell the exact numbers, but the car stays at 14 until about 4500 RPMS, then jumps up to 14.8, maxing out at 15.5 at about 5700 rpms. It goes back down a bit more when it gets closer to redline.

My question is...what kind of an A/F ratio should I have on the car, and what can I do to richen the mixture up a bit? Right now I'm thinking that I need to have the fuel injectors cleaned, change the fuel filter and check the fuel pump. Then check the AFM to make sure it's working properly.

The car only has a few power mods done to it, it's mostly stock. It has the stock exhaust manifold going to a Racing Beat cat replacement pipe, and a cheapo muffler. I also have a K&N cone filter on the AFM, but haven't yet gone for the full CAI route yet. That's all I've done to it, but I don't know the past of the car so who knows what the previous owners have done to it.

My other thought is this...the wideband O2 sensor is connected to the muffler pipe, and I'm pretty sure I have an exhaust leak where I didn't tighten something correctly when I did the cat pipe install. Could that have thrown the sensor off?

 

exhaust leaks can totally fubar your settings and make your car backfire like hell. really depends on how far the leak was from the sensor.

 

that is about perfect if 14 is stoic you're perfect from what I've learned we make the most power just lean of stoiciometric above 5k, so you should be okay for now. anything below 16 is scary, below than that you're puurrrfect..