Hey everyone!

So I am experiencing an issue that I am having a hard time diagnosing. My 1996 Legacy (Ej20h TT engine - MT) is stalling after about 20 minutes once the engine has warmed up. The idle is rough and the only way I can prevent the engine from dying is by giving a bit of gas. Otherwise I get the chug chug, chug chug and dead. At some points the engine almost sounds like a cammed V8 due to the rough idle and vibration is pretty aggressive.

Some background:

I fixed an oil leak coming from the oil pump a couple weeks ago. Prior to this, it ran very well. Once I fixed the leak, re-timed the engine and put everything back together, I cannot get it to run right. I opened it back up and redid the timing to be safe. I was extremely thorough with my measurements this time around, but no change. The vehicle runs and drives when cold without issue, but immediately takes a turn once warmed up. I do not have a CEL and am not getting any codes after plugging in the diagnostic wires under the steering column. What is the deal!?

Not long before all this, I replace the following: spark plugs, coil packs, knock sensor, coolant sensor, cam position sensor, crank position sensor, TPS, O2 sensor (passenger side/left side). I cleaned out the MAF, so my next step is to clean the throttle body and look for vacuum/intake leaks.

Any help is appreciate.

Thanks for your time!