Thinking about going MS, school me.
 

I bought the car on this setup:
AEM Fuel Ignition Controller (dyno tuned)
BEGI Adjustable Fuel Pressure Regulator
305cc? Supra Green Top Injectors

The tune has always run rich, about 10-11 AFR's at full throttle in boost (10psi). As of yesterday, my AFR's start to go down to 13ish but creep up as high as 15. Ofcourse I let off and don't get on it, but it isn't good. A CEL has come on (still need to scan it), but as of now I'm not going to drive the car. It seems like it's got a misfire or slight hesitation. Any idea what could cause it? BEGI AFPR? I've been worried about running a piggyback system ever since I bought the car, so maybe now is the time to upgrade to a Megasquirt. Only thing is, I've never tuned or even looked into tuning a car. I'd like to open up a program on my laptop to look at my current tune to see why it leaned out recently, but I don't even know how or what to look at if I did that.

Anyways, what Megasquirt would you recommend? From my understanding, all I would need is some 550cc injectors, and then I could get rid of the stock ECU, the AEM piggyback, and the BEGI AFPR if I got a Megasquirt. I figure this should help me narrow down or even fix my issues. I don't know how to tune though, so that scares me as well. I don't want to put a Megasquirt together myself, I want to buy one pre-built that will be plug and play. I guess I'm just trying to figure out what to get, where to go from here, and how much I'll be spending. I'm in college, so the budget isn't big, but I feel like I need to get this taken care of.

Any responses would be greatly appreciated, thank you.

A tune doesn't "go bad" unless it was bad in the 1st place. Sounds like you have hardware issues, and while I absolutely recommend going ms I'd suggest you fix all the crap wrong with the car before trying to slap an ecu you don't know how to tune onto the car to "fix all your problems". After that, and when your car is problem free, read through the megamanual, and the various diyautotune writeups/how to's. It will overwhelm you with boatloads of valuable info on ms and definitely help you make a selection. After that, you can decide how involved you want to get, whether to buy a mspnp, diypnp, ms2, ms3, etc. Up to your knowledge level, motivation level, and wallet. For your car I'd say there's the biggest selection of available megasquirt iterations. Just my .02

Totally understandable, and I do agree. It's just aggravating when I've been trying to fix all the janky stuff on this car for months, I just want it running good and I would rather just pay to have it fixed correctly at this point.

I'm not sure what kind of hardware issues you're talking about, but hopefully I can trace it down.

Check my edit.

also you mention your car just recently started "running bad" or having issues. figure out what made it do that after running decent for a while. the ecu only controls the components. doesn't fix them.

It's a loooong story and has so many variables. Tough situation all around, I mean the ECU has some butt connectors holding wires together. I'll be fixing those soon.

I'll be sure to keep reading up, although most of it is hard to comprehend. I was leaning towards a PNP setup, as it seems to be the easiest. I might make a few calls around here and see if anyone does tuning for the Megasquirt.