My 99 chevy malibu Clean out lifters

If it has a miss then I would check for a valve problem such as bent valve. I am not sure if it has a pushrod type motor, but a bent push rod could cause a miss also. If it was mine I would first run a compression check as this should verify or eliminate from the diagnosis a valve problem. Collapsed lifter also could cause a miss. You might try putting a can of Rislone in the engine oil and see if it fixes the tick. I'll bet the miss and the tick are related.

Bob

add a litre of diesel and a 3 sec squirt of fairy washing up liquid ,use vehicle for a week and see how it sounds ,if its quietened down a bit ,change the oil and use a cheap diesel engine oil and then add some more diesel and fairy and leave another week ,if it still hasnt quiented down then strip and repair ,is has quietened down the change oil again for good measure and use the diesel engine oil as its a detergent oil and then change oil at approx 6000mile interval no longer and use the cheap oil .Change oil filter every third oil change and you will not get a repeat of the problem.Use an expensive long life oil and the problem will re appear ,because the additives and combustion residues will clog up and stick the hydraulic valve lifters