Do you have any engine problems? I.E. rough idle or periodic loss of power? Judging by eagles thread count I'll bet hes no longer online or has found a larger forum dedicated to montes and luminas. I'm in the market and don't own one as these yet, but if your engine is running rough it could be the vacuuum hose to the modulator or IF these cars are electronically controlled it could be MAF, TPS, ETC. I'm not for sure, but I'm guessing these have the 4t60-E transmissions? Is your MIL light on? Even if it's not and it's intermittent you may have stored codes. Find out if your trans is electronically controlled, (You would know by the -E of the transmission type, or you could call the dealer) if it is your cheapest route (Free) would be to go to your nearest autozone and see if you have any codes. That's where I would start. Good luck