Engine knocking my engine started knockin while driving and i stoped to check oil and water leaks... it was full of oil and water. knocking sound is coming from bottom of the motor or underneath the cab

https://www.autocodes.com/p0172_honda.html this link is for your code ---but as to the knocking sound sounds like over heating and you have engine damage --check for leaks [[the valve sounds like a petcock for draining system ]] and before trying to fix code check and test the cooling system compression valvetrain oil for water infiltration and plugs for water fouling

sounds like a rod is knocking, check oil to make sure it is full. If it has plenty of oil then if it checks out ok, you probable need new engine.

ok on todays automobiles the gas cap does more than just seal the gas tank. Now they run a return line to the tank. this does 2 things. it returns un used fuel and vapors back to the tank , and it pressurizes the tank to help improve the fuel pump.

Now as it is possible running without the gas cap may cause problems I am not 100 % positive that is your only problem.

It sound like the knock sensor is detecting the knock you mentioned and is trying to retard the timing to fix it . In doing so it has retarded it to far causing the engine to loose power and eventually stall. I would first replace the gas cap. then run a good gas additive to a full tank of gas to clean out any water and dirt that may have gotten into the tank while the cap was off. now the issue of the knock as you described. is it a knock or a ping? A knocking sound is loud metallic hammering noise. a ping is a ting not very loud. if it is a loud metallic sound I would have a reputable mechanic check it soon, as it could be a serious issue. Ping can be caused by bad or weak gas or cheap low octane gas. I would run a mid grade gas in it and see if it fixed the issue.

Sounds like a tapping maybe lifter. Maybe valve check under valve cover.

I had a 76 Cadillac years ago that did that to me once. Took it in and found out it was completely out of oil. Have you checked your fluids?

it could still be a rod even if its full of oil. carbon build up inside the engine can cause a knocking sound but its probably a rod. does it go away after it starts?? if it only does it while starting, it could be leaking water in a cylinder after you cut it off and the next time you're cranking it, its trying to compress the water

That doesn't sound good. It appears you have 1 of 2 issues. The no coolant is a bad/blown head gasket or cracked engine block. When the head gasket is bad or block is cracked the coolant leaks into the cylinder blows out the exhaust (have you noticed the smell of coolant or white smoke in the exhaust) then runs by the pistons and into the oil pan (check your oil level it is probably way high) where it mixes with your oil and reduces its viscosity/lubrication. After prolonged driving with coolant/water in the motor your bearing will wear prematurly and cause parts to become looser then they are (hense the knocking sound). If you continue driving with the knock the motor will have a mechanical breakdown and more then likely throw a rod. THis is usually a motor swap at this point. Some mechanics will replace the bearings but either or you will nee extensive work to correct. The head gaskets need to be replaced/checked and the head for warpage/seepage and possibly a cracked block plus fixing the damage to the lower end. Its usually cheaper to purchase a new/used motor as this is somehting that will cost $1000's of dollars so please pick a reputable mechanic for this kind of work... If you have an extended warranty this is the time to use it..

the pully that the coolant is leaking out from sounds like your water pump. with no coolant in the system the temperature gage wont read the correct temperature. replace the water pump and pray that the engine didn't overheat, as to do permanent damage.

sounds like an engine bearing has bit the dust,

ok did the knocking noise speed up as you pressed the pedal? if so id check the oil first and see if that helps at all and if it continues to make the knockin sound you might have a thrown rod/piston. The oil can effect the the pistons being as it is the lubricant for the pistons to move up and down in the bores(cylinders) but the low oil would only cause the engine to start knocking if there hasnt been any oil added as needed for a long while. has you engine got hot or warmer than usual? the could also be a symptom of low oil.