If a lambda is gone, cleaning it generally won't help you ot mate, they aren't like spark plugs where you can clean off the carbon and your good to go, the actual probe is inside the casing, so if it's got carbon build up, or saturated in fuel (it will if you've got a kill switch on the coil pack to send fuel straight through the engine and out the exhaust for your flamer). They aren't cheap though, so it's alot to spend if it's not that.
I have no clue how the flamer kits work, so I can only try and advise on what you've said, but if it's a switch that stops the spark, then that pure fuel going through the lambda will register as very rich conditions, so will make your lambda register a fault.
I would reccomend taking the battery off for 15mins to reset the ecu (make sure you have your radio code as you'll need to enter it when you put it back on), that will turn the mil light off. Don't use the flamer kit, & see if the problem persists. If it does, then try th following.
Start the engine, & 1 by 1, take the leads off the coil pack, & replace before you move on to the next. If you have a thick rubber glove, wear it, as a precaution, but I've done it without and been fine. As you take each lead off, you should hear the
engine note change. If not, then your coil is not functioning correctly. You can hold the lead real close to the coil pack tower it came from (i'm talking almost touching) & you should see the spark jump from the coil into the lead. That's how you can tell if the coil pack is working properly.
My money would be on the lambda though mate.
k:
