unkown engine mod

[Netskimmer]

I have a question about a modification a previous owner has made to my 2000 Trans Am. There is a socket in the upper air box (I think that what it is, I'm not terribly experienced with car mechanics yet.) I believe it is a sensor and there is a plug that looks like it should go in it but is unplugged, the plug was wrapped in electrical tape. I unwrapped the plug and found something stuck in it, perhaps something to make the car think it is still plugged in. The car runs fine and has done so since I bought it about a half a year ago. I was curious as to what effect this is having on my cars performance if any and if I should take any action to change things. I have pictures but I can't upload them.

[Morley]

Sounds like the inlet air temp sensor (IAT) has been unplugged and jumpered so the ECM thinks the air temp is cold all the time. This will let it run richer, but I doubt it has any real benifit.

[Netskimmer]

Will this cause my engine to run hotter? Should I plug the sensor back in?

[Morley]

Originally Posted by Netskimmer

Will this cause my engine to run hotter? Should I plug the sensor back in?

It will cause it to run richer and probably fail emissions testing. The only real reason I can think of for someone doing that is because the owner was using regular gas and was using the rich condition to stop engine knowk. The problem is that any money you saved buying regular gas instead of premium is blown by making it run richer.

[Netskimmer]

So what your saying is that I've been running premium in an unusually rich mix all this time and that there is no boost of any kind, performance or otherwise. Would I get better gas milage if I restored the sensor since it would no longer be running so rich?

[Morley]

Originally Posted by Netskimmer

So what your saying is that I've been running premium in an unusually rich mix all this time and that there is no boost of any kind, performance or otherwise. Would I get better gas milage if I restored the sensor since it would no longer be running so rich?

Yes, your gas mileage should increase with the sensor hooked up, provided you don't have a lead foot.

[Netskimmer]

I usually baby it...usually. I reconnected the sensor and drove to the store and back. I could tell no difference in performance but I did not go far enough to tell if it impacted my fuel economy. I guess time will tell. Thanks for the help guys.