Air Bag Suspension Kit for 2021 Toyota Sienna

Updated 07/07/2025 | Published 07/18/2023

Question:

I’m looking for helper spring for 2021 Toyota sienna 4weel drive which one will fit my van

asked by: John

Helpful Expert Reply:

We do have an air bag suspension enhancement kit that fits your 2021 Toyota Sienna with the Firestone part # F4155 that you referenced.

expert reply by: Jameson C

Dee

6/20/2025

This is a really interesting point, especially since I’ve also been told by etrailer representatives that the F4155 kit isn’t compatible with the 2021 AWD Sienna due to interference with the bumper stop on the vehicle. However, I noticed in etrailer’s installation video for the 2022 Sienna that the technician removed the bumper stops. What confused me was the placement of the F4155 plates—he installed them on top of the air bags. Wouldn’t they just fall out without anything holding them in place? According to the instructions, the plates should go beneath the bags, with the air line routed through the center of the plate to secure it. So which method is actually correct for a 2021 AWD Sienna? Installing the plates underneath seems more logical.

Jameson C.

6/23/2025

@Dee Actually you are correct it's not listed as a fit for the AWD models. If the issue is the bump stop then yes that being removed would work. With the weight of the vehicle on the suspension though the plate would not fall off.

Dee

6/23/2025

@JamesonC is there and issue with installing the plate on the bottom of the bag for this vehicle?