Just got my FD up and running. I through on a new downpipe, highFlow cat, then exhaust...Car is running super lean and it idles funny. Will an AFC fix it or do i need a computer..? Anythoughts would be great

 

The s-afc is nice....but keep in mind that when you up the boost, you usually take out a couple degrees of timing. I'd just drop the 450-500 for a aftermarket ecu and be able to throw all the bolt-ons you can at it. CJ

 

Don't get the S-AFC and don't drive your car hard as it is. You need to lower your boost back down to 10 psi in order to avoid running lean with a high-flow cat. Whatever you do, don't open the intake.

You can control boost with a good controller like the AVC-R or go ghetto with the home depot controller.

 

So my next step is to get an upgraded ECU..? new to mazdas soo im clueless..before i put the cat on it was running super rich, now its dangerously lean....>

 

You would'nt beleive the amount of people who have popped a motor due to putting a mid pipe/high flow cat on it without uprgading the ecu......CJ

 

like I said, you need to lower your boost to 10 psi or upgrade your ecu. It's that simple. You need to go through the links in the newbie sticky before you blow the engine. Since you say you are new to Mazdas, the FD requires care when modding to avoid running lean, as the stock ecu does NOT make adjustments for running more boost than stock.

Also, turboed rotaries are supposed to run rich. The stock FD runs 10:1 or less. You should be shooting for about 11:1 when modding.

 

may i ask how you know you are running leaner now? did you check the plugs or is this just a guess? How much boost are you seeing? And describe what you mean by it idlign funny. Even with those mods, it should idle just fine w/o an upgraded ecu. the idle fuel map doesn't need to be changed when you add mods.

Danny