ProjectWhiteTJ, did the crankshaft position sensor fix your p030* problem? Thanks in advance.
I first got the flashing check engine light on the highway one day. It went away immediately. Took it to Autozone and the scan turned up P0300, P0301, P0303, P0304, P0306. I changed plugs, still got the codes. Changed the plug wires, distributor cap, rotor. Codes were gone for about a week and a half (long enough to pass inspection
Then... I was driving home on the highway again today, and the flashing CEL comes on again but stays on this time, which is way more stressful. I did my best to check every single rubber hose under the hood, but honestly, it's hard to understand what the hell all the vacuum lines do. I wouldn't be surprised if there was a freaking vacuum hose connected to the brake pads, steering wheel, spare tire, turn signal......etc. I found nothing out of the norm, whatever that was. Couldn't hear any obvious whistling (though there is a fan blowing the hell out the engine bay all the time so it makes it hard to hear).
I guess it's time to start trading out sensors. Seems like there would be a more specific error for the O2 or crankshaft sensor? Isn't there a better way to solve this besides throwing money at every electronic part under the hood? Even so, I'll probably start with the O2 sensor because my mpg seems a little low and the engine feels like it is running rough (though I really have nothing to compare it to as this is my first TJ with an I6). If I just take out the O2 sensor will it look "dirty" or burnt out" if it is - in fact - bad? It also starts hard on cold startups. Sometimes I actually stop turning it over because it takes so long. Warm startups are fine.
Thanks for the update/answers.