Originally Posted by SS LS1

The later year engines also received better exhaust manifolds and slightly better cylinder heads, BUT the '01-'02 cars have a LAME factory tune that sucks the top end power out of them. The '01-'02s are factory programmed with a high octane timing table that is as bad as the '98-'00s low octane timing table when running on bad gasoline. The '01-'02s really wake up with a little computer tuning.