I have a 99 Camaro ls1 that was running a little sluggish when I bought it, ive played around with a few things on it. it came with no cats, egr, and a trinity tuner. I did the normal tune up to try and get rid of it with fuel injector cleaner and all. then by mistake I left the maf unplugged yesterday and the car has all kinds of power and runs a lot smoother. anyone know why this is and will it hurt the cae to run like this?

 

Is your screen still in the maf? First thing I'd do is get some maf cleaner from autoparts and clean the maf.. The maf when unplugged runs closed loop so that's why you see a difference.

 

Have somebody who knows how powertrain controls work explain it to you.

The PCM runs in closed loop mode regardless if the MAF being plugged in or not. With it unplugged, it's running strictly in speed density mode...and should also be using the lower-advance spark map while the MAF error code is active.

Cleaning the MAF sensor element internals is a good next step, especially if the car's had K&N or other oiled cotton filter elements in it. The oil coats the MAF internals and interferes with accuracy.

If you can get access to a scanner, read the Long Term Fuel Trim (LTFT) percentages for Bank 1 and Bank 2 while idling and driving. Repeat w/ the MAF unplugged and note the differences.

 

the fuel banks with maf plugged in sometimes get to 25.00.
when unplugged the highest ive seen is 9.00. I have removed the sreen and also tried cleaner on it. im so confused by this and sometimes the ses soon comes on after about 20 miles with unplugged, but doesn't change power. the big power loss is when it plugged in.

 

My next step would be replacing the MAF with a new GM piece. +25% trim is maxed out, and if removing the MAF from the system corrects it then the MAF is the most likely culprit assuming none of the wires are damaged.

 

I have trinty in car that shows my fuel banks

 

Pace Performance (vendor linked on the left side of the screen) should be able to get you a replacement MAF at a decent price.

 

With a tuning suite like HP Tuners and a wideband controller you can tune your VE table to run perfectly without the MAF. That's called Speed Density tuning and what you revert to with the MAF unplugged. It is not better or worse than MAF tuning done right. Even if the car gets it's MAF issues nailed down a proper SD tune will make the car run better in transitions. GM uses a hybrid of MAF and SD normally with MAF in steady state and SD in transitions.

 

All great responses folks but of course this is the internal engine section. You know, pistons, rods, cranks...

This would've been better in https://ls1tech.com/forums/pcm-diagnostics-tuning-7/

 

I've pretty much given up that fight, the zombies win.