Tuning and/or Deleting

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I’m not planning on doing either of these things any time soon. They’ve been on my radar, but ultimately I don’t want to effectively void my powertrain warranty yet. Even though the Magnuson-Moss Warranty Act theoretically prevents them from completely voiding it, it is pretty well known that they will use any ECU tuning to void out major engine work. If it weren’t for this, I would have tuned long ago. Some of the “hot” tunes can run +200hp or more with only a simple lift pump, but I’m not looking for that. I have had my eyes on a +40hp tow tune that tunes the engine and transmission better for towing, and reduces turbo lag. In my opinion, does what the factory should have.

I will eventually do that, probably in a year or so after I have another 12K miles on it. To accompany that, I’ll convert from the CP4 to CP3, add a lift pump, and Edge CTS3. The CP4 fuel pump is the thing that scares me most about not having a warranty, but it’s expensive to replace. $1600 or so in parts, even more in labor or do it yourself and it is a huge pain to get to. The CP4 was a cost-saving item that they introduced to replace the CP3, that has had high failure rates and fails catastrophically. Not only does the fuel pump fail, but when it does, it sends shards of metal through the entire fuel system, often requiring $12K in parts and labor to correct the damage. There are lots of reports of this happening over at DuramaxForum.com, but for a while I dismissed them as fairly uncommon. Then I realized that I had the same fuel pump in my 2010 BMW 335D, and it was the reason my car spent a month in the shop (under warranty). Definitely not taking that risk here. When the CP3 fails, it usually spares the rest of the fuel system.

There is a lot of debate of emissions in-tact vs non-emissions tunes, referred to as “delete” tunes. These trucks have very complex emissions systems that include re-circulation of exhaust into the intake and particulate filters that are inline with the exhaust. When clean air to the engine and as much input+output as possible means the best running and longest lasting engine, this technology is generally frowned upon by a lot of owners. There is a huge aftermarket for removing all that technology. However what is best for our engines may not be best for the environment, and the EPA threatens to fine you if you remove it. Most places do at least visual inspections to verify that these systems are in-tact during annual inspections, which is what prompted this post for me.

In Travis County, Texas, one of the most environmentally progressive areas of the state, these are supposed to be visually inspected and I thought tailpipe emissions tests performed. I just took my truck in for inspection and they did neither. I left my house, drove 5-10min to the shop, and was still back home in a record 24min. They did little more than check the blinkers, and didn’t look under the truck or under the hood at all. No testing of the exhaust.

I decided not to go with the delete tune because I believe that the EPA regulations are only going to become stricter over time. Even if I can get away with it now, or for another few years, at some point I am sure those regulations will be enforced across the board. I’ve heard of officers at traffic stops doing visual inspections for the DPF devices on the exhausts, though I’m sure that is few and far between. But one of these days it could be common practice, and I don’t want to get into having to worry about that. At some point I will do an emissions in-tact tune, with some supporting mods to prevent catastrophic damage, and call it a day. But that won’t be for another year, or 12K+ miles.