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Diesel Truck Parts And Accessories

2004.5 - 2005 Chevy GMC 6.6L LLY Duramax Parts

Since the initial release of the Duramax powered Chevrolet and GMC pickups, the auto manufacturer has been making big waves. With the release of the 2001, they were the first pickup to feature a commo ... read more

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Since the initial release of the Duramax powered Chevrolet and GMC pickups, the auto manufacturer has been making big waves. With the release of the 2001, they were the first pickup to feature a common rail injected fuel system. Beginning with the 2004.5 Duramax LLY (and relatively unchanged with the 2005 Duramax) models, they ventured into variable geometry turbos for the first time. And while Ford may have beat GM to the punch with VGT technology for the LLY Duramax turbo, it has been proven that the GM platform is substantially more dependable compared to its competitor. Even with the numerous changes that have occurred to Heavy Duty GM's over the years, they have actually done an excellent job of keeping a relatively unchanged platform. Sure, there have been tweaks and upgrades, but not completely different engine platforms, displacements, etc. that cause the buying public to wonder what they are really getting themselves into, in other words, they are PROVEN.

And for those of you with this model of Duramax, we've got good news for you, there are TONS of upgrades available for this truck. Whether you want to make it faster, more fuel efficient, last longer, haul a heavier trailer, handle better off road.....you name it, we've got the components and knowledge to make it happen! While most enthusiasts, and even non-enthusiasts for that matter, have heard of the injector failure rate issues that plagued the 2001-2004 LB7 Duramax, the good news is that all issues were addressed with the LLY. Now, that’s not saying you’ll never need to replace your Duramax LLY injectors once the miles start accumulating, but the failure rate is substantially less. Further, upgrading the injectors to a higher displacement unit with an optimized spray angle can deliver you big gains in power and even fuel economy! This upgrade paired with optimized engine calibration, such as through EFI Live Duramax LLY, an Edge Juice with Attitude or Evolution, PPE Xcelerator, and so forth, can completely change the driving characteristics and power for the better.

Attention: If you have a 2004 Duramax please verify your engine type before ordering any product. You will either have an LB7 or an LLY, and this category is specifically tailored towards the 2004.5-2005 LLY Duramax engines.

To verify, check the 8th digit in the VIN number:
If it's a 1 you have the LB7 motor and it is covered by the model years 01-04
If it's a 2 you have the LLY motor and it is covered by the model years 04.5-05

Products in this section are designed to work on 2004.5 and 2005 6.6L GM Duramax equipped trucks unless otherwise noted.

We get a lot of calls and e-mails each day with various product, vehicle, and installation questions. Some are completely off the wall and can even catch us off guard at times, but many others are fairly routine, so we thought we'd post some of the most popular questions that can hopefully be a good resource for you.

Q: I have an EFILive AutoCal from another Duramax. Can that same tuner work on my LLY Duramax?
A: In short, yes! Autocals get linked to the tuners computer so if you are not getting the same company's tunes, you must get it unlocked first by the original tuner so it can be locked to the new tuner. After that, a new VIN license must be purchased to open up a slot on the tuner. And tunes must be purchased for the new vehicle. They would be sent to your e-mail along with instructions to load them onto the tuner.

Q: I'm looking at an exhaust kit on your website, but it doesn't state which cab and bed configuration it fits, will this fit my application?
A: In most cases, unless it is specifically stated as fitting a certain configuration, all exhaust kits on our website will fit all cab and bed lengths. Further, most kits will not fit cab and chassis applications unless otherwise noted.

Q: I'm looking at this 5" (or other) exhaust kit, but my truck only has a 4" exhaust now. Does this 5" exhaust include an adapter / reducer?
A: Yes, the exhaust systems we sell will adapt down to fit the application at the designated starting point (turbo back, cat back, DPF back, etc.) for a hassle free installation.

Q: What are EGT's?
A: EGT stands for Exhaust Gas Temperature, which is the temperature of the exhaust leaving your engine. This measurement is typically measured before the turbo to ensure you are not overheating components. For most applications, we recommend not exceeding 1300 degrees.

Q: Do you offer smoke and lope tunes with any of your preloaded EFILive AutoCal options?
A: No we do not. In short, both smoke and lope tunes create these results at the expense of the overall reliability of your engine. The tuning companies we have chosen to partner with are top notch and are most intested in creating increased power, fuel economy, and overall drivability. We at Diesel Power Products invest a substantial amount of time and effort to ensure that the products we recommend are in the best overall interests of our customers and their trucks, and unfortunately, these types of tunes do not align with that overall goal.

If you've got a question about your Duramax, feel free to give us a call at 888-99-DIESEL and we would be happy to assist.

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