spark plugs needed replacement check engine light goes on and stability service engine power less trans shift erractic will not go over 30 to 40 mph
The spark plus are of less concern until you get the other problems diagnosed. If the CEL is blinking, have it towed. If the CEL is steady and you want to chance it, you can have the codes read and post them here. Include all the normal stuff too- -engine and mileage.
Are you saying these problems started after changing spark plugs? It’s very unclear.
If so… did you used the factory/OEM replacement spark plugs? I’ve often found that strange things happen if I try “upgrading” to some new whiz-bang spark plug which the engine wasn’t designed to use.