Hey all,
I'm having a rough idle problem with my Cherokee that just started a day ago. At first I was driving and stopping at red lights and everything was normal, but then out of nowhere at a red light the Jeep started to idle rough like shaking the steering wheel rough. An engine code wasn't thrown right away, but continuing to drive it caused a 351 code to be thrown. I took the negative off the battery to reset the system and drove it and stopped a few times to get the engine to running temp, and then let it idle for like 10-15 mins. it started idling rough again but no code. Also, while I'm idling my oil pressure gauge doesn't quit moving it keeps flucuating between 25psi and 40psi. What's wrong with my Jeep? Thanks for the help in advance.
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https://repairpal.com/obd-ii-code-p0351

I'd start by looking over the plug wires, distributor cap/rotor, and the coil. The oil pressure sensor may be bad, and more likely than an actual oil pressure problem.

 

Spark plugs?