P1706 Lock up clutch does not engage

I searched the forums for "P1706 Lock up clutch does not engage," and it seems like I'm the only one with the problem. I purchased a Titan electronic caliper from Northern Tool and the shaft is at 6.1 mm, but the CEL code is still there after disconnecting the battery for a few minutes. I saw on a CRV forum about how some people like me, never down shift to D1 or D2. I tried that a few times. Also, the shift cable needs to be looked at, but I don't know what to look for.
But then I also have a P0401 for the EGR, which I just cleaned out yesterday by taking off the intake manifold & running drill bits, straws, brushes & carb cleaners through. I cleaned the EGR ports, took off the battery, and the check engine light went away. I'm still expecting for the CEL to come on again. Is it true that disconnecting the battery for 15 minutes will not clear the CEL or ECU?
I'm also getting a P1457 for emission control system leak, and tried tightening my gas cap with 10 clicks. Again, the code came back on the scan.
I'm mainly concerned with the P1706, just wondering if others have had this issue before. Perhaps it's a common issue? Maybe it's a simple fix?

a battery disconnect will clear a CEL, same as pulling fuse #13 in the passenger fuse box. it will come back on if the issue is serious enough. the car would have to be driven over 40 or 45 mph for 10 seconds, then 10 seconds off the gas for the light to come on. if it comes on right away, there might be another code.

i've had a P1456 for the past couple summers (summers only...at half a tank of gas only). if a different cap doesn't cure the problem, it could be something else that's clogged. thats where my troubleshooting ends since i dont care enough to go any further. i recall something about a vent line getting clogged since the cap is part of maintaining pressure in the tank...something like that.