Do performance chips work?

I found a performance chip for my 2005 Nissan Maxima SE. It states an increase in fuel efficiency of 4-7mpg. Do these chips work and if so can they damage the ECU (Electronic Control Unit?

No, and probably not.

I’m a skeptic. How can you measure any performance differences? The marketing people rely on “placebo effect”. Since you spent the money you expect to feel a difference, an improvement. You’d need a dyno to measure any hp or torque improvements. Measuring mpg isn’t an exact science either without good controls and measurements. You feel a difference, that really isn’t there.

Can it damage the ECU? That is a possibility. Have you priced a new ECU?

If you found this chip on eBay or any number of other sites it’s a scam. EBay is absolutely plagued with this junk.

Don’t you think that if this miracle chip provided even a 1 MPG increase in fuel efficiency, much less 4-7, that the Feds would have mandated it on all vehicles long ago?

No I haven’t priced a new ECU. I was just hoping to squeeze a few more MPG’s out of the $3.00+ gas we are now buying. If ECU damage is possible, then I will not get a chip.
Thanks for the info!

This may be illegal. Some performance drop is associated with preventing emissions from exceeding mandated limits. If the chip causes your car to exceed emissions set by the manufacturer then you owe the feds about $5000. It is not legal to do most of these chip mods. Some chips or program changes are allowed. Like if you buy a car at sea level and move to denver then the dealer is allowed to adjust your programming. But changes for performance may violate the emissions laws. They can be used in off road cars that are not licensed for road travel. Meaning you put it on a trailer to take the car to a private track/trail to drive it.

Many claims are made.

Read through that seller’s feedback and you will see not only the ones who discovered the truth but also the delusional ones who think it actually works.
It’s a .5 cent cent resistor. You can get a grab bag of them (Qty 100 or so) at Radio Shack for 5 bucks or something like that.

Likely a scam. Did you find this on a web site that list ‘chips’ for all makes and models? They’re BOGUS. Carmakers spend millions of dollars to increase mpgs by small amounts. Do you this some fly-by-night company has the ability to instantly increase mpgs ‘4-7mpg’ at low cost? Nope, no way.

If it’s the crappy resistor that you put across your temp sensor to try and fool the computer, it will likely not do any real good, and may cause driveability and emissions problems. It probably won’t harm the ECU, but it’s worthless. If you shell out some money for a performance tuner, like a “Diablo”, it MAY give you better performance or economy (one at expense of the other), but can possibly cause damage to the engine or catalytic converter if not used properly or you’re just unlucky.

There is no way you will get 4-7 more MPG with the “performance chip” If there was a way to easily do this, don’t you think that Nissan would have happily added this feature to your car to help them meet federal fleet standards? (and sell more cars too)

Don’t waste your money. If a chip could increase fuel economy then it would be on the vehicle when it left the factory.


With all the regulatory pressure on th emanufacturers to increase gas mileage, they’ve already programmed the original systems to get the max possible while still running properly. The best you can do is keep it properly maintained and serviced so that it continues operating properly.

Performance chips exist to gain HP and torque, not mileage. And this is for a normally aspirated motor so all they can really do is change the fuel curves and idle. Now sometimes mileage does increase slightly when doing this (maybe 5%), but no where near what they are claiming.

Skip it.

Thanks for the reply, I will probably skip it as suggested.