* 2002 WRX automatic transmission
* approx. 16800 miles (27000 kms)
* mechanic tightened gas cap, test drove car, cleared code
Came up again in the same week:
* approx. 16840 miles (27100 kms)
* tightened exhaust hose from TSB 09-36-03
Immediately after the CEL came on I noticed a significant decrease in the car's performance. Later the mechanic said that this is because the car goes into "safe mode" with that particular code.
The first CEL happened only a few days after the same garage performed the work on TSB 09-36-03 "Fuel Smell in Cold Weather". In the end it turned out that they had incorrectly installed the hose mentioned in the bulletin and this was triggering the P0457. Wish they had checked that the first time instead of telling me I wasn't tightening the gas cap properly!
For more info on that TSB, check out this topic: