Tuned my 1999 gmc sierra after I did a cat delete, ran much better after that. He also listened to what i wanted, tuned it for towing and modified the shifting tune on transmission as well, trans was shifting a little weird before the tune, got it tuned and after a fluid flush it shifts like a dream. Very nice, answered all my questions professionally and thouroughly.

Sent a car in to be worked on gave them $5,000 to fix the motor they fixed it, blew the motor when they put it on the dyno. Gave them another $5,000 for them to build me a brand new motor too to bottom and did the same thing. They are not willing to work with me on pricing and say it isn’t their fault. They blame it on faulty equipment. I have heard that I am not the only person this has happened to, just wish I would have known sooner. DO NOT TAKE YOUR CAR HERE!!!

$10,000 and still don’t have a car I can drive. They blew my motor on the dyno after they built it. Built a new one and blew that one too. Asked to put the car at 1000 hp and the turned it up to about 1200 go, blew the head and kept running it. They blame faulty equipment and will not work with me on pricing. This place is worthless if you want to drive off the property.

Dry nitrous and purge kit installed which took them over 10 hours to do on a Cadillac CTS? Ran me about $1200 in labor alone!! Ripped off yea I know. The kit to this day still doesnt work properly. For a professional Performance Shop was not told about needing different spark plugs nor needing a tune.They seem to take advantage of individuals who are just learning. Also upon inspection the nitrous line running into my intake wasnt even fastened properly. The line legit fell out. Do not go here unless you want to overpay for mediocre work. There are plenty of other tuning shops in the area which I just learned about recently. Take my mistake and learn from it go elsewhere.

Ryan did an excellent job at tuning my vehicle in the matter of a couple hours. Thank you!

Ryan is the only one who I know and trust to get what I want out of my 87 Trans Am. Could it be because hes a Pontiac guy too? 😉

Ryan has always been great to deal with, very helpful. If I have a question or concern, he doesnt brush me off like some others would, hes a busy guy but gets back to me pretty quickly. Eric, Mike and the other guys up there are always great to deal with as well. Never had a problem with this shop, I would suggest them to anyone especially anyone needing performance work done.

When I called, they were easy to set up an appointment with, they were super friendly, and were able to get me in and on my way quickly. The 8.1 in my truck has never ran better! The tune is awesome. Driving, towing, screwing around, it has more power than I thought you could get out of a simple tune! I am amazed! Will be coming back in the future with other projects. Thank You KC MAXX!

Ryan Mitchell and his team at KC Maxx are absolutely amazing! Ryan isnt your average tuner that thinks his knowledge isnt worth sharing. He treated me with the utmost respect and didnt make me feel like an idiot when it came to what I already attempted to do with my tune. He actually helps you get better and shares his knowledge with the customer. His criticism is very constructive and teaches you right and wrong. Hes also very quick and precise with his tunes and even took the time to do some street cruising to make sure the drivability was spot on. I would definitely recommend KC Maxx Performance to anyone for any vehicle.Thank you to everyone at KC Maxx for doing what you do!

Ryan tuned my GTO, got a decent gain Im happy with and hes a really nice dude. Would recommend! Price of the tune was the best I could find around KC too.

Went to fix a start up issue. They told me it was one thing after the other. Then $2400+ later they said it was my fuel pump which I replaced last year. My car is exactly the same as it was when I brought it to them and they want to keep trying parts with uncertainty and refuse any refund. So now I have to file a lawsuit.UPDATE: they issued me a refund that was fair for both of us

Yet to be determined. I was told they would get back with me tomorrow with some prices. Hopefully it is a 5 star.

This aint a rating, but i do have a question. Do you guys tune or can dyno tune a Veloster N. (Korean hatchback.)

Great people, very friendly and helpful!

Not good at tuning cars for street. And instead of fixing or retuning they continued to try to replace other parts to take my money... do yourself a favor & take your car to justtune.

Ryan has tuned literally dozens of cars for me over the years and everytime its killer service! The team makes you feel like family and really cares about your service. Would recommend to anyone looking for top notch performance!

Given total and Donnie failed to return change then claimed he changed the plugs for $260 and did not. But rest assured when he gave the refund he gave exact change. Vehicle was also kept for one week before it was even looked at after scheduled appointment. Would not recommend.

Very personable, down to earth guys who make sure you meet your goals! I 10 out of 10 would recommend! They also take the time to educate you on what safety items you need and why! The work speaks for itself, stellar to say the least!

They did some work on my Saleen Mustang, great service, nice and knowledgeable staff. This guys can do what many others couldn’t! Highly recommend and definitely will be back!Misha N.

Awesome service and very knowledgeable for all builds

These guys know their sh*%. Theyre a pleasure to work with, professional, and have answered every question I had. Ryan is a legendary tuner, and his shop has done good work. I wish them the best.

Had a very bad experience here. The customer service is not great at all. 1st: Car left with a check engine light which was never on ever since I have owned the car. Even when the car was untuned before it went to kc maxx it was never on. Over my “02s not reading correctly” which was never an issue with this car. Second: Ryan and I had a conversation the night before it went to him. That I was putting brand new 02s and plugs in before he got a hold of it. And he said great that would be a good idea. Well I go to pick the car up, and on my bill, they wanted to charge $200 for a plug change which I later found out they did not do. I asked for my old plugs so I can see them because they said they were fouled. They gave me an old set of mix matched tr5 and tr6 plugs that they probably had just laying around. Also they gave me 6 old plugs. Not all 8. Third: After every drive cycle when the vehicle is warm when I go to start it. It wants to die and takes a while for it to find its idle. Pretty embarrassing. I would not recommend this place for anyone looking for work being done.

Had my 02 trans am tuned and would recommend them to anyone. Ryan was very informative on what he did to the car and made some suggestions on future mods. Thanks again for everything .

Ryan Mitchell and his team at KC Maxx are absolutely amazing! Ryan isnt your average tuner that thinks his knowledge isnt worth sharing. He treated me with the utmost respect and didnt make me feel like an idiot when it came to what I already attempted to do with my tune. He actually helps you get better and shares his knowledge with the customer. His criticism is very constructive and teaches you right and wrong. Hes also very quick and precise with his tunes and even took the time to do some street cruising to make sure the drivability was spot on. I would definitely recommend KC Maxx Performance to anyone for any vehicle.Thank you to everyone at KC Maxx for doing what you do!

Awesome experience. Car drives great. Will be back after some enhancements.

Great place for Performace and basic automotive services. Always have gone above and beyond for me and others that I have seen

They are the only shop on KC that I trust with my car. The tune is awesome, 706RWHP and it has great drivability. They are real pros!

I got a wild hair to add a 500cc Subaru/ Aisin AMR500 supercharger to a little Suzuki 1600cc 8 Valve TBI engine. The normal go to fuel/spark management ECU is the Megasquirt systems. KC Maxx is the only tuner in the Kansas City metro area knowledgeable about the DIYAUTOTUNE Megasquirt ECUS. Between Matt Cramer at DIYAUTOTUNE and Eric with KC Maxx, I was able to gather the knowledge to build my system. For the record, when Eric was spending generous amounts of time educating and advising me, I had yet to spend a single penny with KC Maxx. Additionally Eric even took the time to get to know me on a personal level. I really appreciate the knowledge, service, generosity of the team at KC Maxx. Beyond Impressed!!

Came in for a remote tune and ran into some software issues which put everything way behind, but the staff was great about it. Dyno is a bit of a heartbreaker, but remember PEAK NUMBERS ARENT EVERYTHING. Prices are fair and the people are very helpful.

Great group of guys, always willing to get you headed In the right direction.

I was warned not to get tuned by kc maxx. Could not find any bad reviews so I did it anyways. Very disappointed in the tune. Street drivability was trash. Told me my trans needed built because he couldnt get it to shift properly. After having the car retuned by a different tuner the car shifts perfectly.

My car had existing issues when I brought it to them. Although curtious and professional I do not believe they fixed my issues like I was led to believe. I completely understand their business is not to fix random issues, it to tune cars. They said they had fixed my issues and was able to dyno my car. I find that hard to believe because my car wouldnt even start without a jump to leave the shop. Also I only got about 2 miles away before the exact same issues began to happen again. Like I said, Im sure they do what they do well but diagnosis is not their strong suit. If youre going there for a dyno they can do that. Also no tune to my ecu was performed. It was all set still at factory settings so I know they didnt try to tune anything for better performance. I understand. I just wanted to get my car out of there and im sure they just wanted me gone too.

Tuning sucked after 2 hours it seemed like they wanted to shove you out the door drivability sucked,hanging idle.You don’t get driveability right doing dyno pulls,waste of money and time had a tuner near me got drivability greateven with speed density tune.Ryan also told me my o2 sensors would quit reading the tuner that done my car said they were reading just fine with no issues.Ryan might be good at tuning drag cars but doesn’t do any good for a street driven car

Only tuner Ill let touch my car. 2 years and still running strong daily.

Great service and great people. I highly recommend them.

Only place in KC to have a LSX tuned. Excellent fabrication skills and experience as well.

Smart guys, real nice . Nice work .

Great guys, knowledgeable, and easy to work with.

Great place and policy.