Car Parking as Taxable Benefit

I work for the NHS and I’m trying to resolve an issue I have with my parking payment affecting my tax contributions. I pay £44 per month to park at work. This is paid via my monthly payslip as part of the salary sacrifice scheme. My tax code for the previous financial year was 1257L. I have received a letter from HMRC to say I am receiving a “taxable benefit” in the form of car parking, I owe them £89.90, and my new tax code is 1213L.

I have the option to change my car park payment to salary deduction. Is this going to make me better off each month? I’m concerned my lower tax contributions are going to affect my pension etc in the future, but also don’t want to change the payment method and end up worse off. Any help would be greatly appreciated! Thanks.