Yep, this one car is a pain. Thought I'd throw out some more symptoms to see if anyone has any ideas. It's also started with the steering wheel shimmy thing. :-( So, I thought I was going to tell that the code appears immediately, as soon as it starts, because it seems like that when I was driving it yesterday on the interstate coming back from Dallas. But just went to check and no, it took several minutes of idling then 3 miles of driving to set as Pending. It turns on the CEL the next time I start it. I've replaced the injectors, upper ox sensor, air filter, and MAF with no change. Took it to a buddy's shop because my TorquePro won't read much data. He's not a hybrid guy, but this seems to be an ICE issue so I thought he'd figure it out. No luck. He says that all of the sensors/events that would set a 0172 are sending the appropriate data. A weird thing: immediately after changing the injectors, the MPG meter went haywire - it shows mileage in the 80mpg range. Seems to be working as far as the meters going up and down, registering electricity generated, etc. but always shows mpg in the 80s. The only things I didn't check from the diagnostic list are the fuel pressure and coolant temp sensor. Buddy said it's not likely fuel pressure since the code is for too rich, and the coolant sensor reads accurately. So, it drives fine as long as I keep clearing that code. When I got it back yesterday from my buyer, the CEL was on and in addition to the 0172 it had misfire codes for all cylinders, so I assume those will set if I let the 0172 code set and keep driving it for a while. My buyer had no way to clear the codes. Anyway, that info probably won't help y'all, so maybe the better question is what happens if I keep driving it like this - just clearing the code every time the CEL comes on. Again, it drives fine like that for hundreds of miles. No misfire codes, just the 0172, and it runs seemingly fine although I'm not getting the MPG data to confirm. Need to do that manually the next time I fill up. I guess what I'm hoping is that whatever is causing the DTC will get worse and finally self-identify. But, of course, I don't want to burn up valves, pistons, whatever. The coolant temps are always normal at 182ish so I don't see an imminent threat. Just throwing the shimmy out there, in case anyone has heard a way to fix it without replacing the steering gear. It's just hard to invest that much effort in these old cars. I got steering gears on my parts car, but taking it off, and taking the one off this car, then installing is more than this old man wants to do. But worse, after getting this car back home, I discovered lots of rust underneath from that Minnesota snow. Trying to remove the steering gear, breaking all those rusted bolts, is not something I'd try. What's weird is this car didn't have the shimmy when I bought it. Drove it all the way from Minnesota to Texas to LA and back to Texas with no problems When we got to Texas, and finally hit rain, I found out the filler tube was rusted through, and I assume water got in the tank from the storm, because it started missing horribly. And that's when the shimmy started too. I stuck the car in storage for about a year before I got around to swapping in another tank/fuel pump, and when I got it running again, the shimmy was gone. I've not driven it a lot since then, maybe a thousand miles over the last year, but it never shimmied again, until now. It almost seems like the shimmy happens when the engine starts missing. I'd be interested to fix the 0172 and see if the shimmy goes away again. I know, dumb, but why'd it go away the first time? I remember the posts about using low voltage to "burn the fuzzy hairs" off the magnets in the steering gear. Did anyone ever try that? Do those "hairs" go away on their own eventually, like when you park the car for a year?
