Got horrible dyno results, how can I reprogram a 05 Maxima?

What sort of numbers? What was the weather that day?

I hope you were using premium fuel? Have you checked to make sure the knock sensor code isn't set? There is no CEL with that code and that will kill the performance as well as using anything other than premium fuel.

How do you fix the knock sensor code?

Try

CD

The results are here:

I was using 92 octane. It was sunny, temp. in the mid eighties. Traction control was disabled.

And the dyno was a DynoJet 248c.

I'm not sure I understand what you meant about the knock sensor.

That doesn't look too horrible to me. Your car was making 210 hp to the wheels at 6000 rpm. Since you have a 265 hp motor, you have to account for drivetrain loss. You will not see 265 hp on the dyno. Also, after

CD

That's what the technician said too. 20% loss! That's a lot. I would have gotten a MT, but the dealer assured me that I would have a very hard time selling it.

Again, that's what the technician said.

How did you know? :)

He's your dyno technician!

The biggest problem is that nissan started encrypting the ecm's. Between that and the the number of variations even within a model year(there are 16 variations for the 01 sentra 1.8L alone), I haven't heard of anyone making more than a dent in decoding the logics used.

Interestingly, the 6 speed manual has a similar drivetrain loss compared to the auto. Autos are the least efficient. The older 5-speed manual (in the 2001 and below Maximas) was more efficient in transmitting the car's power to the wheels.

And as for the drive wheels, FWD is the most efficient followed by RWD and lastly, AWD.

I've done a few dynos myself:)

CD

Yup, around the 98 model year. The ECU literally turned into a black box!:)

CD

The other thing is they dyno corrected for temp and altitude? The 265HP number is at the flywheel and at sea level in dry weather at moderate temps. Those aren't "horrible" numbers..