2000 Mitsubishi Montero backfire

scan for code and check fuel pressure with a gauge auto parts rent it

It sounds like you have a camshaft follower or camshaft lobe that has gone bad. I would remove the spark plugs and do a compression test to see which cylinder is low and then remove the valve cover to inspect the valve train, here are two guides to help us see what going on.


https://www.2carpros.com/articles/how-to-test-engine-compression

and

https://www.2carpros.com/articles/engine-backfires-while-running


Check out the images (below). Please let us know what happens.