My 1998 4.0 4x4 Ranger is misfiring bad at idle and 40 to 50 mph it also is loosing power. I took it to a mechanic and he quoted me over $2000 he said it was showing running lean bad camshaft position sensor and two injectors were going bad, said he would have to run compression check on it. Could it just be the sensor causing this problem? If not I need recommendations on a good crate motor lol.

I know the 4.0s have timing issues. I was told that in order to fix it you would have to take the engine out. A misfire can be a result from bad spark plugs or the timing. If you want to go with a new engine I would see if a nearby ford dealership or look to junkyards maybe. Sorry this isn't a lot of help.