...of all things, for I/M readiness. This doesn't make sense - the only time the battery could have been off AFTER that was already checked to be okay was at the subaru dealer to which the used car dealer took this car to get the recalls fixed (which, oddly enough, still show up as needing to be fixed... whatever). Since then I've driven over 300 miles in a number of different trip types.
Before I bought it, there was a point when I looked at the car, the readiness was all good, but it had a front O2 sensor code - P1131. They took care of this.
On my way home from failing inspection, not even a mile away from the inspection station, my CEL comes on. I check it when I get home (after getting gas), and Learning View says P0420. What? Why didn't this show up until right after a failed inspection? Coincidence?
One last bit of information: The reason I pulled the rom is because I already had my laptop in the car over the weekend - I was concerned with some of my timing. At the dealership, when I discovered the P1131, IAM was at 1, and the individual cells were all over the place. Over the weekend, I checked again (I filled up with 93 octane not too long after driving off the lot, and the fillup that I did after getting the code was with 92 octane - this second fillup after the LV session I'm talking about) - the IAM was up to 15, and the cells had calmed down a bit. When I checked just now, IAM was 16, only a few cells had any activity, and it was all minimal. Now, I'd imagine this could be caused by a bad tank or a tank of regular put in at the dealership?
Oh yeah, and the car's entirely stock.
So, #1, what caused the I/M readiness to take that long to get back? Would pulling the rom with ECUflash or doing learning view reset things?
#2: What causes P0420 besides bad cats? What causes it to come up suddenly like it did?
#3: Let's just say that I had a friend with a wrx. He doesn't like to obey the law, or environmental ethics. Let's just say he went into the rom using romraider, and put checks on all the nice little CEL disables and the force readiness thing. Would the MVC be able to tell that he did this? Would they pass him through inspection? Would there be any potential damage to his car as a result of bad cats that went undetected? I'm assuming he would re-enable all the DTC's after he passed inspection, so that he could make sure his car continued in working order.