WE FIX WHAT OTHER SHOPS CAN'T
Custom HP Tuners Performance Tuning — Fort Smith, AR
Mail-order tunes from someone who's never seen your truck are how people lose engines. We tune what we install. Cam tunes matched to the cam in the engine, AFM/DOD disable that actually sticks, idle and drivability cleaned up, MAF and VE tables corrected for your build.
Call (479) 434-5852 Try Live Assist — $20 AI diagAbout the shop
Address
5300 Towson Avenue, Fort Smith, AR 72901
Phone
HoursMon–Fri 8:00 AM – 5:30 PM · Sat 9:00 AM – 1:00 PM · Closed Sun
Service areaFort Smith, Van Buren, Greenwood, Barling, Alma, Muldrow OK, Sallisaw OK
OwnerRobert "Doc" Holmes — two decades on a wrench, ASE Master-level diagnostics, HP Tuners certified.
Why Dr. Underhood
Most independent shops fight over brake jobs. We fight over the work nobody else wants to touch — electrical gremlins, AFM lifter failures, custom tunes, programming, advanced diagnostics. If three shops have already looked at it and nobody fixed it, that's our job.
And if you can't get to Fort Smith — put the car on the phone. $20 gets you AI-assisted diagnosis using a real mechanic's case data. $99 gets you a live video call with Doc.