general rule, OK to mod and wont ruin warranty are 1. wheels change ( do not touch suspension..once you change suspension..warranty is gone) 2. catback 3. adding strut bar once you change factory setting- even with proof of dyno and reflash map and evidence of suspension work..your warranty is gone
Nonsense. Warranty isn't an "all or nothing" deal. If you change the suspension, the suspension obviously won't be warrantied anymore, but it won't affect your powertrain warranty. And vice versa. Tuning your car won't affect your warranty if you blow a stock shock.
As mentioned earlier in this thread, Toyota wont cover the modified part (obviously) or any part directly affected by the modified part. Everything else is covered. I have personally had warrantee work done by Toyota on my Hilux complete with suspension lift, bigger tyres (that munched the trailing edge of the front bumper), ECU tuning, etc, etc. They were OK with it and even commented on the modifications so were fully aware.