Not sure which 2004 Mazda 6 In-Line Modules are right for you? We have over 1502 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"I installed Unichip about two weeks ago. I def. notice a performance boost. Especially from 4-6000 rpms. I checked my gas mileage after 162 miles. I got 1 at most 2 mpg. The velcrow didn't do much for me and I couldn't get the strap to to hold the unit in place. I think it's holding well enought though. I might go out and get some more velcrow." —Grant G from New Holland, PA bought an Unichip Performance Chip for a 2004 Mazda 6.
"This was a great purchase. I have an intake and exhaust and the chip was tuned for both items. There was a definite increase in WHP and torque. It took about 20 min to install and only two days to get to my house with free shipping. Great product and service!!!!" —Matthew R from Renton, WA bought an Unichip Performance Chip for a 2004 Mazda 6.