Hi guys, just after a bit of advice as I'm near my wits end with my 09 JK.
For about a year now I've had an issue where about a minute after ignition I won't be able to accelerate any faster than the current speed I'm at. This only seems to happen at slower speeds, say when I'm in a 50-60km area, and it usually kicks in when I have to slow right down eg. to give way at an intersection. If I've still got a bit of momentum, I can usually keep it going at around 20km/h. After about 10 seconds, my engine light will flash along with the audible ding, and suddenly it's like a rush of fuel comes back and away we go again as if nothing happened. If my speed is too slow and I can't keep it moving, I just roll to the side of the road out of the way of traffic, turn the ignition off and back on, and most of the time that fixes things until next time.
I've experimented sticking the accelerator flat to the floor whenever this happens, it makes zero difference to my speed, and usually results in a pop/light bang sound coming from who knows where. Then when we're back to normal, you can smell the excess fuel from having had my foot down, like there's been a major blockage. What confuses me is how restarting the ignition or just waiting it out seems to fix things.
Not long before this all started, I had an O2 sensor error code (can't recall which sensor). My local mechanic believed this wasn't related so I didn't pursue replacing it at that point. I'd also been getting "multiple misfire" codes (hence the engine light flashing/dinging) from whenever the power loss occurred, so had all the spark plugs replaced, which has fixed the misfiring, but the power loss remains.
Took it into a Jeep dealer for a closer inspection, they say there's no voltage coming from any of the O2 sensors, and they're guessing the PCM is the issue and needs replacing. Three mechanics and a couple of grand later, I'm hesitant to keep throwing money at it. I'm scared to even trade or sell it on as I'd hate for someone to lose power in the middle of an intersection (as I have a few times now). So I'd appreciate any advice or ideas. I'm not great when it comes to the tech side of vehicles, so let me know if I've not made anything clear or you need more info.