lindaw1953

have a 01 grand cherokee and Ive replaced the plugs,wires and coil pack replace the sensors and the wires up to them still cant get the stupid thing to go off codes keep saying the cylinders are misfiring not all at the same time just one then another one so I started to run high grade gas in it still doing it what can I do now and then to top it off my oil pressure drops when its idling and goes back to normal when im driving it getting really flustered with the nickle and dime crap but I love my Jeep

Condonsation

Check engine light comes on...checks engine. "Yup, still there!" Lol maybe get a compression test done??

Creature85

Are you losing coolant or have overheated recently? A cracked head could cause a multiple misfire. Your 0331 head is prone to cracking so do like Condonsation mentioned and get a compression test done.

basegrinder

try a new gas cap?

Bustedback

Take it to a shop, you have no clue of how to diagnose the problem. You'll save money in the long run. Low fuel pressure and vacuum leaks are just a few things that can cause a misfire code. There are mechanical things, such as valves that are not sealing, that can cause a misfire. Take it to a shop.

lindaw1953

had it in the shop they said wires, plugs and coil pack well Ive changed all but Im wondering if there is any connection between the oil pressure and the check engine light does anything have to do that would cause both problems what about a vacuum leak