The M20 can handle a huge deal of timing before anything really pops up, and that you were still getting pinging with the stock 173 chip leads me to believe that it would be some issue outside of the tune. But who knows.
If I'm reading right, the stock 173 ECU gave you slight pinging, but the 153 gave you none? And you only went 1 tooth over? IIRC 1 tooth is about 3' of timing.
If I'm reading right, the stock 173 ECU gave you slight pinging, but the 153 gave you none? And you only went 1 tooth over? IIRC 1 tooth is about 3' of timing.
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