the car has 137k on it. I was going to check it out mainly as preventative maintenance, but the car is idle a little rough at times. mainly when driving, and I come to a stop, the idle will dip down and then come back up. I just cleaned the MAF and TB earlier today, so I'll see how it runs tomorrow. The only thing I KNOW is on its way out is the serpentine belt, so I need to replace it soon, but would that affect idle like that?