Cyril, maybe you can answer this one since I've seen previous posts of yours listing an air intake sensor mod...

As I understand it, chips basically work by changing the cars computer reading of the air temperature by overriding the air intake sensor and adding power by allowing more fuel into the engine. From what I've been told it might be slightly harder on the engine than normal, but nothing worth losing sleep over.

Well, there is a kit that was recommended to me to use on the Crossfire. However, this kit COMPLETELY disables the air intake sensor and eliminates any signal to the computer at all... So I'm curious, if this doesn't just kick off the check engine light and / or disable the car to begin with, and if it does work... what damage could this do? Because, even though I do not know alot in this area... I don't see endless amounts of fuel being poured into the engine being a good thing, or the air sensor being entirely disabled being very good either... But I've been told it won't do any damage... Please help me out here.

 

If you permanently disable the sensor (ie disconnect it and replace with a resistor that always reads "cold") the ECU will eventually find the fault and you'll get a cell. the ECU has strategies: ex. on cold start coolant temp and IAT can be compared...on a cold engine they should be about the same...if there is a big deviation it will set a code and possibly go to an emergency map = low timing and dump fuel with the goal of preventing knock. These cars have electronic throttle, the ECU if it detects a big enough "problem" may limit throttle opening (limp mode). Otherwise it can check for open circuit (disconnected sensor) short circuit (resistance too low) and sometimes simply a lack of sensor change over time will set a code. Even if the ECU thinks the sensor is ok if you over-advance timing you'll hit the knock sensors which will pull out lots of timing and/or dump fuel to control detonation...resulting in reduced power output.

If you wish to try this (I don't recommend it) I'd suggest a circuit that on startup allows normal sensor output, then switch in a resistor to change resistance to a colder temp indication once the car is in closed-loop mode, then turn it off prior to shut-down. And change your oil often if you run excessively rich...you'll get fuel in the oil.

A better strategy would be to log the stock IAT, compare it to ambient temp, and find a way to make it cooler/stay closer to ambient (ie CAI, shielding, etc.).

 

I'm not saying that toying with the IAT isn't a dumb idea, because I believe it is...
However, I do disagree with the fact that the ECU will throw a code during startup if the coolant temp varies too much from the IAT. In variances between the coolant and the IAT, there are only 3 possibilities, they are the about same temp, the coolant is warmer or the IAT is warmer...

In the first case (~same temp) there should be no code thrown as this would reflect a cold engine starting normally.

If the ECU threw a code in the second case (the coolant being warmer), the ECU would throw a code every time you started a warm engine.

In the final case (the IAT being warmer), well lets just say that if you purchase this mod and it makes your IAT read warmer than your coolant, you've been robbed.

With all that being said, *some* GM ECUs are programmed to recognize that if the IAT reading is -20 degrees, your coolant temp should not be able to reach 185 degrees when it's that cold outside unless something is wrong. However this only happens about 8-15 minutes after the car has been running and takes about 40 miles after that to clear.