legacycentral bbs

I'm almost sure I posted about this very briefly within the past week but the search feature keeps bringing up the debug mode. So, anyway, here goes with more details:

On my '93 ss AT, I came up with the CEL code 41--faulty learning control system. I have to check injectors, air flow sensor, water temp sensor, throttle sensor, O2 sensor, fuel pressure, and possibly replace the ECU according to the FSM. Trouble symptoms for these systems would be erroneous idling, engine stalling, poor driving performance, etc.. Basically, my car would be running horribly. But it's not.

So, after thinking about it, I cleared and reset the ECU per Josh's (Legacy777) writeup. Then I went into D-check and no codes flashed at all! I was happy and the car ran better than ever. This was this past Thursday.

Yesterday, Friday, I started up the car and drove it up and down my street twice. It started bucking gently to moderately on gentle acceleration. Then the CEL went on solid. I went back home and did the black connector check. Code 22 (knock sensor) came up. That's as far as I got due to my work schedule.

So, I have two questions:
1--Why didn't code 22 come up originally with the D-check mode?
2--Should I go ahead and replace the knock sensor or is it possible that more codes may come up as I drive the car?

Oh yeah, the car is legally not road-worthy for the last 7 months since I haven't had time to really work on it. Registration expired on Dec '06 so I really cannot be driving the car around much. I don't mind driving up and down my street since it's a quiet, private residential street but no more than that.

One more thing, before the CEL came on, the car had so much power that it truly surprised me. It pulled REALLY HARD upon moderate acceleration! It actually pushed me back into the seat.

Any thoughts would be appreciated! Thanks!

OK, I repleced the knock sensor with a new one since the one on the car was cracked bacly. Then I cleared and reset the ECU and boy does the car have gobs of power now! However, it now knocks going uphill and 3/4 to WOT really badly! Naturally, I let off on the accelerator so it doesn't continue to knock.

The engine didn't knock before probably because it was in limp mode. But why does it knock now with a new knock sensor? Does the ECU need to "learn" by driving the car more before it stops knocking?

Also, all the CEL codes have been cleared and none come back up. However, the CEL keeps flashing rhythmically at 62 times a minute. Nothing in the self-diagnosis system apparently is now defective but what other areas that affect the CEL should I check? For example, a loose gas cap could cause the CEL to go on, but mine is tight and it holds the pressure.