Ive searched all the threads and couldnt really get a definitive answer. I have an 01 xe, 3.3. Recently ive started to notice a tap, or a knock. It sounds lik its in the valves. Also, when i start it up in the morning, the exhaust is very rich and almost smells like some bad gas. Ive been wondering if my valves need adjustmnet, or replacing, or if its time for the timing belt. I have around 90000 to 93000 miles. Have to double check. Also, would a bad spark plug gap have to do with this. im interested in the new E-3 diamond fire plugs. Any one tried these? How hard is it to do a volve adjustment?