Misfire after clearig CEL
 

I was getting codes P1124, 1126, 1128 ad 1130 on my 1998 mauak, so I tried blocking off the line to the vacuum cannister/SAI loop to troubleshoot it, I confirmed no leaks in my patch on the plenum, and the car was running well. That is, until I cleared the check engine light.

As soon as the light was cleared, the car wouldn't idle anymore, running with a severe misfire. After a minute of keeping it afloat to see if the DME was adapting, I got a flashing CEL for misfires on all of bank 1. (0300, 0301, 0302, 0303)

Now, I know whatever was causing this was previously being compensated for by the DME, because it was running peachy before I cleared the codes, idling smoothly with A/C on or off, and all around behaving itself.

Does anyone know what might be happening here? This is my daily driver, I only did what should have been a simple and easily reversible procedure, and now I'm dead in the water. Any information would be greatly welcome, as of right now I'm afraid to run in whatever state of tune is causing such a severe misfire, as I don't want to be running severely lean or rich for that long.

I tried reconnecting SAI, and that didn't help.

I also tried disconnecting the battery for an hour and doing the key procedure (1 minute ignition on without engine on, remove key 10 seconds, start) to reset the ECU, also to no avail.

It seems pretty clear to me that I didn't fix the problem I had previously, but what's more clear is that there's a new problem, and I can't begin to imagine what it is, other than the car having previously adapted to the small vacuum leak and now being completely unprepared for it.

I'll have to drive the wife's car to work for the foreseeable future, it seems.

Try unplugging your MAF sensor and see if it will idle and run smoothly.
When you unplug the MAF sensor if forces the DME to a default fueling strategy.
If you have a vacuum leak causing the issue the engine will not idle well on that default fueling strategy.

Thanks, I'll try that when I get home. If I don't have any luck, I'll proceed with teardown of my intake plenum, I have the blanking plates to delete the SAI loop under it and then I'll get a chance to closely inspect the whole vacuum system while eliminating the cannister and associated rat's nest. Hopefully, that whole process solves it or at least gives me some clues. If not, coils/plugs are next, and then AOS. Last time I tried to troubleshoot, it got worse without the MAF, but we'll see what it does with the vacuum line blocked off.