Isuzu Repair: 93 Trooper loud ticking from bottom of engine, worn piston rings, piston pin

Question
QUESTION: 1993 Isuzu Trooper S SOHC with auto-trans/4WD @ 95000 miles. I've got a loud ticking noise coming from the driver's side/bottom side of the engine. I'm using Auto Rx right now in the oil, and it has worked wonders for cleaning the engine, and it's very quiet now (except for the ticking). Bottom-end torque is way up there now and driveability has increased exponentially, but this loud ticking persists. Yes, I know it's probably a sticking lifter, but this noise is coming from the bottom of the engine.

I've ordered a bottle of CerMax ceramic engine additive which I've heard can help.

Also, I'm getting dismal mileage, so I'm going to change the EGR valve, TPS, AIT sensor, O2 sensor and air filter.

Any ideas?

Thanks.

ANSWER: Well is it a ticking noise actually or more like a thumping or a slapping sound?

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QUESTION: It's not really a slapping sound. It sounds just like lifter noise, but the location of the noise is what confuses me.

Answer
Well the ticking noise is most likely a worn piston pin or piston. If it stops when the engine is warmed it is an unevenly worn piston/rings. Or a bad timing timing belt/chain sprocket. Although if it clicks faster when the engine speed increases. Then it is a piston pin(maybe a connecting rod) Allen.