94 sl2 erratic ticking high idle

ok so i bought a really old sl2 from a friend 60k on engine but 215k on tranny and chassis my friend told me when i bought it the engine light was on for the egr he had a friend check it but it ran fine and im a poor high schooler trying to get by so i let it go a month after i bought it i drove it into a pond that had flooded over the road in the middle of the night. got it running again and its has had some electircal problems but other than that it just has a very high idle at 1200 and cold start runs to at least 2000 and 2 days ago it started having a really erraric ticking noise that comes and gos but is worst at idle but you get it going and it goes away the noise comes straight from the engine im thinking either the throttle body needs to be cleaned or the vacum on the egr is shot or the tps is shot and i have no idea on the mad ticking noise thats going on my best guess on that is its needs a dam good tune up done if anyone has some insight it would be very much apperciated.

did you check the oil??? Did you replace the oil after you drove it through the water?

yes of course first thing i did