Cars running weird

[GTDrifter]

So I have a 2000 RS with a 2.2 recently it has been bogging at low rpm. doesn't matter if its wot or gentle throttle. It only does this after the engine is warmed up. No CEL, nothing weird going on with the engine temp. Also when accelerating in 2nd and 3rd gear between 4-5k rpm it sounds like the horn is on for about a second?

Recently installed an oil catch can. There was some oil trapped in the line so I disconnected the catch can and put the regular hose back in place so my guess is that was the cause but don't know where to start with repair.

Any ideas?

[GTDrifter]

forgot to add that when it bogs/sputters it backfires and the car idles perfectly normal

[1996Battlewagon]

Is this ONLY with the catch can on? Are you running a 2.5 ECU with your 2.2?

[GTDrifter]

Catch can is disconnected and stock hose was reinstalled...dealership did the swap before I bought the car so not sure about the ecu...I've been driving it for a year and a half without issue so I doubt that's the case

[GTDrifter]

so today I changed the oil and filter even though its only been about 600 miles, moved the catch can lower in the engine bay and hooked it back up. Pulled out of my driveway and it sputtered in first second and third gear...on the way back home it only sputtered in first gear so hopefully the car fixed itself

[GTDrifter]

Found the cause...bad spark plug in cylinders 1 and 4...replaced with Bosch platinum...old on right new on left

https://sl-i.net/FORUM/images/imported/2011/11/IMAG0403-1.jpg