No idea of the cause of the gas pedal vibration. Might check it for any stored codes. Could just be some bad gas, a computer issue, motor mount, throttle sensor, etc.
Please don't change out your stabilizer. The stabilizer is not CAUSING the issue- so why mask over it? Sounds like a lose track-bar, balancing issue, worn out control arm bushing, etc. I would check to see if anything seems lose. Look under (lie under the front end) while someone turns the steering wheel full lock left and right. Look at the control arms, pitman arm, track-bar, etc.
Will a lift void a warranty? Each dealership has their own criteria, regarding what will and will not void your warranty- at least in terms of whether or not that particular dealership will address an issue under warranty. As a rule of thumb- if a certain modification can be determined (by said dealership) to have caused a failure to another component of your Jeep- then they can make the call that due to the modification- that repair/ replacement will not be warrantied.....but again, it really depends on the dealership and whether or not they are off-road/ modification friendly. Best way to know what your particular dealership is willing to do.....is to simply tell them what your intentions are, and ask them if those modifications will void your warranty. A good dealership (off-road friendly) will in most cases not say (for example) that larger tires or a suspension lift is the cause for an engine or electrical/ computer problem....but say you have an issue with your axle or wheels- then they might certainly say that the aftermarket suspension lift was the culprit.
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