2013 GMC Sierra 2500 HD Duramax LML. They did the CP4 to CP3 fuel pump conversion and added an Air Dog Lift pump. This is definitely a quality shop in terms of their knowledge and ability. I will not hesitate to bring my truck in again if I need work in the future. read more

Honest and fair prices and good work. Finished the repair when they said they would and did a good job. I will definitely go back when my other trucks need repairs read more

I own the dreaded 6.4 diesel. These trucks can be hard to find mechanics willing to work on them. I've owned since new. The two previous shops who helped with repairs are excellent shops, just I moved away. So searching for a new shop I came across Xtreme Diesel. Not only did they repair my 6.4 diesel, but I suspect the repairs found were missed by two very good previous shops. Additionally I found their electrical and vacuum system diagnostic skills to be extremely advanced! Never since brand new has my truck ran better. I can't express enough the gratitude to these guys for their service, dedication to the craft and I am a customer for life. Thank you! read more

BEWARE! NOT WORTH THE HASSLE OR MONEY! Charges $165 per hour and told us the truck was fixed. My son was in class so he went in the day after to pick it up and the truck wouldn't start! He told me over the phone that it was simply a wire disconnected from the battery that drained it. So, after my son paid the $252 bill and the truck would STILL not start (we had to have it towed there), the guy on the phone started yelling at me, cussing, and hung up when I asked him what I paid for then if the truck still wouldn't start. He yelled something about getting a new starter and he was too f***ing busy to fix it and to get it towed because he didn't want our business. I called back and another guy hung up when I asked for the owner's name and phone number. My mechanic from home called him (my son just moved to Chico for college), even my home mechanic said, "Sheesh, he's lovely to deal with. He shouldn't be cussing at customers and saying he's too busy to deal with fixing things". He refunded the money but gave us all the worst experience any of us had ever had. Do not waste your time or money...if you are looking for the worst day of your life, take your business here! read more

Jason knows his stuff. Most honest guy, easy to talk to, gets prob fixed right; what more can I say. I brought my diesel in and it was running like crap. By the time I got it back, it felt like new... Actually better than new because of a slight upgrade. It has never been so powerful and fun to drive! Anyone not giving five stars, it's not an Xtreme Diesel problem, it's a "YOU" problem. Likely, you don't know your stuff and therefore shouldn't be reviewing. That's my honest opinion, unless Jason does a 180 with other people (I only know him by bringing my truck there due to a recommendation). Besides, it has to be a five star because he has tons of work and people who go to him, that's based on the fact that he's always got a full lot of vehicles for him to work on. But he moves through quickly; I never have a long turnover, and one of my issues was not so small. Keep it up, man. My '05 Powerstroke Crew LOVES YOU!! -Kyle read more

Best place I've ever taken my truck to get worked on. Knowledgeable, fast, and best customer service I've experienced with a shop. I own a Duramax and would trust the guys at Xtreme Diesel with my truck any day of the week. Highly recommended. read more

I went to a few places both in Chico and Oroville to see how comfortable I felt with them and for quotes. The quotes for labor (I purchased the new muffler and exhaust brake myself) seemed so steep I was about to do the work myself... I called Aftershock Performance in Chico and they referred me to Jason at Xtreme Diesel. I called Jason then went in to briefly discuss what I was looking to have done. When I called, he came across a little hard to talk to. When I went in, he's just extremely quiet. But, after our short conversation, I got a better sense of him and felt I could trust him with my baby (truck). After 28 years in law enforcement, I don't do so easily. His price was EXTREMELY fair considering the outrageousness I was quoted by the other places. He's earned a customer here. Big shout out to Aftershock for their honesty and for the referral to Jason! read more

We took our truck in hoping to get it up and running again.Xtreme Diesel owner said he could do it.But when we said we were on a budget due to spending so much on multiple repairs he didn't want to service our car and told us to take our business elsewhere. We had just gotten it towed there and had to pay for it so we asked him to just fix our truck. We received our car a few days later and paid $1999 and our truck was still having trouble.We asked if he could look at it again and fix the problem since we paid so much money to get it repaired by them.We just wanted our car repaired for how much we spent. He said he had multiple cars ahead of us,so we would have to wait and didn't bother giving us an appointment to get back in.He was very rude about it and finally said we would have to order the original part for the car and have to pay for labor AGAIN! What is that!?We have never heard of that from any car repair shops besides this one! We should of known when he was rude and told us to go somewhere else with our business. Never again will this place get our business and if you think we were the only ones treated this way well I have attached a similar incident with a bad review for this place!! We had better luck in Sacramento who fixed the problem without any difficulty or complaints. read more

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I just had my Cummings diesel repaired at xtreme diesel and could not be more satisfied. Jason is a very hard-working man and spent many hours diagnosing my problems. He was very fair with his prices and time. I would never go anyplace else, if you want honest repair this is the place to go. As you probably know there are very few places to get diesel repair. The other company that's been in Chico for quite some time on Highway 99 has a very bad reputation. My personal experience with the other company motivated me to seek out a new repair facility. My grandson recommended xtreme diesel, he is much smarter than he looks. Thanks xtreme diesel - YOU ARE THE BEST! read more

We took our F250 diesel to Jason at Extreme Diesel to get a repair done that we had actually priced out up in Paradise before the fire. Jason diagnosed the problem correctly and did the repair for hundreds under the previous misdiagnosed quote and our truck is running much better. We decided to take it in again a month or so later as we were going to take a long trip and wanted to be sure our old truck didn't have any new issues. The shop was busy as always and Jason had it over night to go through it completely. When we picked it up he said he had cleaned the engine because he found some oil leaking somewhere, discovered the problem ...fixed it ... We would highly recommend this shop to everyone with a diesel especially a 6.0 Ford . This shop is the best in repairs diagnosing and pricing! Thanks Jason and the team at Extreme Diesel read more

Great service. Good guy. I've taken my truck to him for various things and always been pleased with the service. Only shop in Chico I'll take my truck to and my truck is my pride and joy. read more

My hat off to Xtreme Diesel. Jason did a great job on my 1997 Dodge Ram 5.9 cummins diesel. Had him do a tune up and now getting the best MPG I have every gotten. Thanks Jason read more