Cold engine start on 2002 toyota tundra

Does it run rough at hot idle ? How many miles ? Any recent work done on engine ?

You may have dirty fuel injectors - once the engine warms up and goes to closed-loop operation, the computer can compensate for clogged injectors to some extent. Another possibility is sticky valve lifters that work better once the oil gets hot - if this is the case you may hear a rhythmic tapping noise in the valve train at idle while the engine is cold.

bad need of a tuneup? like new spark plugs, ?
172 , is 02 rich/ lean warning. this one is low oxy for rich.
this code can just be a victim. for sure , with misfire.
means 02 sensor stuck at rich,
what is water temp in engine coolant, at failure? less than 150F?
could be lots of things.
leaking injectors, bad fuel.
injector sticking> causing misfire.
id use a scan tool and watch all sensor when it fails.
too high fuel pressure.
misfires cold, but only luke warm cold starts not fully cold.

just one DTC, no P0300 or 30x misfire codes, not even P0300 pendings?

You have a defective valve lifter or lifters.

your doing good if you have 245000 miles on it,the lifters or tappets loose there prime and flatten out it is not uncommon for dodge to do this.if the engine runs smooth leave it alone.other wise you would have to replace internal parts,u could try to put some tranny fluid in the engine before your next oil change ,only 1 quart though.dont run to long 15 to 20 minutes.if tap does not go away you probly have worn internal parts.not much u can do besides replace lifters,big job.

Nope, normal on start up is 60 PSI and once warmed up drops to 45 psi. Have the oil pressure checked for a proper reading during start up's when the engine is cold. As for the lifters ticking, that may be a sign that the engine was ran with low oil pressure or no oil and the lifters are damaged, or low oil pressure and the lifters are starved of oil. Try not to drive it and have a proper oil pressure reading, low oil pressure will damage the engine by having the main crank bearing to spin which is a engine replacement. Good luck and keep me posted.

Count your blessings that it starts. It sounds like the cold air is affecting the idle mixture. Check the hose running from the manifold to the air box to see if it is intact. If not, replace/fix it so that you pull warm air in as soon as the engine heats up.

can be a big fix. youmay want to try a motor flush (engine oil)

Does it have a check engine light? It should. If so get it read. Most auto parts have a scanner, and will be willing to read it for you.

check air filter for dirty , how many miles or kms have your car? , maybe need to replace spark plugs, try to reset the ecu for a momentany malfunction, remove the negative battery terminal few minutes and reconnect,start engine and drive, check if lights goes off , please write me