For years I thought my car had bad heat soak โ€” the throttle would go weirdly soggy on hot days. Turns out the programmable ECU was incorrectly retarding ignition timing at low engine loads instead of high loads. Moral: if you put something tweakable on your car, be prepared to get fully edumunkated about it.

The stock tune (and all tunes I've seen) retard ignition at high temps and high loads to protect the engine. For some damn reason the values were also swapped or copied to the idle/low load table. The car had been dyno tuned at a reputable shop, but even so their focus was probably more on power than drivability.

Seriously, this caused me to buy and swap parts in and out, tweak the raw ignition timing tables, and even buy a 2nd car so I could drive something that didn't stagger around like it was punch drunk.