Join Date: Aug 2006
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The race ECU should come with software, but I've never used it on a 3rd gen so I don't know how much adjustability there is. I'm guessing very little, since the race ECU is still locked. The PCV would tune air/fuel and the ignition module would change the rev limiter and also timing, since you don't want the race ECU's timing settings if you're not doing kit cams.
Yes, stock ECU needs PCV or similar for air/fuel. An ignition module isn't necessary if you're keeping the rev limit & timing stock.
The QS can go directly to the PCV, or you can use the OE QS plug, which will still work with either ECU. My tuner recommends using the OE plug since it cuts fuel and spark. The PCV only cuts one of them, I forget which.
The main benefit to the race ECU is ditching the ABS pump & hardware. If you're OK either manually turning it off every time you cycle the ignition, or you'll leave the pump and cap off the lines, a stock ECU should be fine.