91 Pathfinder

gas tank gets low the engine will start having a hard time idleing. When I undue the gas cap its like a vacuum cleaner (sucks a lot of air). After that it runs good again. Is this an issue with my gas cap or something else? Any help would be appreciated.

Sounds like the fuel pump in the gas tank might be weak.

Thanks, that was one possibility I was considering. Even if it isn't the issue I may replace it just to make sure I don't have a problem with it down the road. Thanks again.

For some reason the gas tank isn't venting right. As fuel is used, air must enter the tank to take the place of the fuel. By guess is someone lost the original cap and replaced (Matched it up) with an aftermarket one that isn't the right one for your car. The first thing I'd be trying is a new cap from the dealer.

Or simply remove the gass cap and see if the idle improves. But yes, the gas cap could be defective or an incorrect replacement.

Uh, he already said it did? :-)

Duh heheh.