Vehicle: 2002 Corolla 5sp, 180k miles
Problem history: Hesitation, burning 1qt of oil every 200 miles, P0420
Repair history: I rebuilt the engine, completely fixed the oil consumption problem, no problems with hesitation for several months (cold months)
Current issue: Recently, with the change to warmer weather it seems, my car has been having some hesitation issues again. After rebuilding the engine I still had the P0420, I thought it may be the catalytic converter but decided not to replace since the car was driving fine. Most of the places I drive take about 15-20 mins to get to which is about how long my car will drive without any issues. It literally drives flawlessly for 15-20 mins but then something changes (switch from open loop to closed loop?). When the issues start, the engine misfires, has lean/rich issues, jerky acceleration, etc. When this started I was curious on what codes it was throwing so I scanned and pulled P0300, P0302, P0125, P0135, P0420(always on), and P0505. I was like holy crap, what's going on. I thought since the car seemed to be running flawlessly initially (open loop?) and then having problems when it warmed up (closed loop?) it may be the front o2 sensor. I had changed out the o2 sensors with Denso's from rockauto when I rebuilt the engine. I decided to go ahead and replace the front sensor with a denso oem from toyota which helped the issue but has not fixed it. What else could cause this? The fact that I can drive 15-20 mins with perfect acceleration and idling and then switch over to misfiring/jerking accelerating/rough idling confuses me. I will be doing some more diagnostics after borrowing a good scan tool from a friend. Anything I should be looking for? Thanks.