Car is a 2002 6 speed coupe with 49k miles.

So after about 45 minutes of driving, (was getting on it a bit, but nothing crazy), my engine light came on. I took it to the local autozone and had them scan my car, and code P0131 came up. Now this code is showing as the Bank 1 Sensor 1 O2 sensor having low voltage, but the guy tried telling me that the car needs a new intake manifold gasket? Can anyone help me out?

 

If the idle is a little rough, take an unlit propane torch and pointed it along the intake manifold gaskets and see if the idle speed changes. You probably need a factory service manual to see the diagnostic instructions for that particular code.

Did he say what led him to the conclusion that it was intake manifold gaskets?

 

It's just what popped up on his system as most likely to be the issue. That's why I thought I'd ask here. The idle isn't rough and the car doesn't smell like gas like it's running rich. Car drives fine like everything is normal. Someone was telling me it could be a vacuum leak?

 

Assuming that the bank 1, sensor 1 O2 sensor reading is correct then it could be a vacuum leak or a leaky fuel injector that's causing the fuel mixture to be giving the bad reading.

I guess you could replace the O2 sensor and eliminate it as the cause. The first thing I would do is clear the code and see if it comes back quickly.