I have a 2004 liberty, im getting a P0175 code. Ive replaced the injector, sprkplugs and the spark plug on the passenger side closest to the firewall keeps getting fouled

MAF (Mass Air Flow) Sensor could be dirty or faulty. Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling Inspect fuel lines for cracks, leaks, or pinches Check the fuel pressure at the fuel rail Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.

Ive tried that and still getting the same code and only one spark is getting fouled. Ive even switched the plugs around and it's just that one cylinder.