Performance mod help

UPDATE ON MOD, I just put a 3.9k 1/2watt resistor on my bros 96 civic and
it did make a difference. But with my car it set off the engine light. But i
got an 3.3k resistor but 1/4 watt and no light, Is the watts making a
difference or not? Also should the idle speed be alittle higher? My car is a
96 Honda Accord lx non vtec.

 

I just looked on ebay some guy said hes selling 2watt resistors. SO the
smaller the worse?

 

Only the resistance counts. The power rating does not make any
difference. The only reason you need to be worried about the power
rating is that you don't want the resistor to get damaged from
overheating. The current through the IAT sensor comes from a regulated
5V supply with a series resistor inside the ECU. A resistor power
rating of 1/8 Watts is sufficient under any relevant set of conditions.
A higher power rating will not be of any benefit, but will not do any
harm either.

 

Well see whats wierd is the 3.9k 1/2 watt set off the engine light, but the
3.3k 1/4 watt did not and they are both in the range of the resistance. See
what i mean? But maybe it was just to close or something?

 

3.9k should be well within the allowed range. Any chance you had a poor
connection when you tried the 3.9k?

 

i dont think so because i tried it twice.