I have d16z6 motor that is having multiple issues. It recently snapped the timing belt. When I took it into a shop they sent out the head and replaced the two exhaust valves in cylinder three. They told me the head was straight changed out the plugs and handed it back to me saying everything was fine. It's now four days later and I've gone through a set of spark plugs each day. It keeps fouling out cylinder 3. I've changed the cap and rotor according to oem specs and its fouling quicker now, and at this point I'm restarting the car every time I hit a stop. What's going on here I'd like to fix this but don't have much cash after getting raped by the shop?