What are the possible dangers of custom tuning?

[rhlow05gt]

I know I'm gonna get a lot of negative responses about this, especially from people who already have tunes installed, but I would like know what dangers there are from having a tune vs. leaving ecm stock. Yes, I know the tune will give me more hp and tq but what do I possibly sacrifice by having the added power? Is it possible my engine won't last as long as it would have staying stock? What parts of the engine could a tune have a negative impact on? I am thinking about getting a custom tune with a CAI but just want to make sure it's not gonna come back to bite me in the a** in the long run. Any opinion will be greatly appreciated.

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[Nuke]

If the custom tunes were dangerous to run, I don't believe 1/3 of the those with tunes would have them. Many here have been running custom tunes and have enough miles on their engines with no issues to substantiate that custom tunes are safe.

Other than the car feeling much more peppy and a slight drop in fuel economy (MAYBE 1 MPG which could be due to getting on it more often whereas a few claim better gas mileage), I can't think of anything else to say other than NOT adding a CAI & tune as one of your first mods is a crime, insane or both ( yes, that means those of you w/o a CAI & tune are probably criminally insane).

[pascal]

Well, a tune too lean=dead engine.

As far as negative comments from people that have their tunes already installed, don't worry...
Most of them only know that it makes the car go faster, so they don't have grounds to give you schit about your knowledge in the matter.
And if they get carried away with negativity, we have moderators to ease things up for you...

Some members with tunes have in excess of 100K miles, so it's proven technology.

[nmd55]

i cant speak to the dangers of a custom tune, but if youre wondering why it doesnt come this way stock the answer is simple. most people dont want to spend the extra cash on 93 octane

[Tylus]

Tuning can do wonderful things.

From the factory the PCM is programmed with an extremely safe tune to allow the vehicle to run on 87 octane (+ or - a few grades) from any source in the country. It is designed to work at any altitude, in any weather extreme.

To do that, Ford had to leave alot of performance on the table to ensure the safeguards are achieved.


By custom tuning, you are providing your tuner with specific input. Gas grade, altitude, weather conditions (ie: you live in Alaska...or only in Texas). These 3 things are huge. Cold weather alone can fry a motor if the tunign doesn't account for it adequately.

ask Roush how many 5.4 3v motors they had to replace in 2004-2005 because of thier RoushCharger tuning was crap for colder climates

Now, when you custom tune the PCM, you are essentially placing the car on the line between 100% reliability, and the chance for something breaking. The closer to the line you go, the more HP/TQ you achieve.

Any tuner worth his salt will get you close to the line, but will back it off a tiny little bit...a buffer zone to prevent blowing the motor, or burning a hole in a piston.

Some crap tuners could care less and they give the customer the ragged edge. These are the ones to avoid.

A properly tuned car will last just as long as a Factory tuned car. You just need a good tuner who nows his stuff. He'll get you the best performance possible and still have that buffer zone.

also, a custom tuned car will exhibit better MPG's and driving characteristics. They are more efficient and easier to drive.

Bad stuff that can easily happen and I've heard about:

1. remove rev limiter - over-rev & blow motor
2. run lean - burn a hole in a piston
3. flood motor - hydrolock piston