2005 Mazda 3 Engine vibration, rough idle, stall
 

Hello members,

Quick background:
- 2005 Mazda 3 2.3L 5 speed ~130k miles
- Has been burning a quart of oil every ~200 miles for 5 years but ran totally fine as long as I kept up on oil

Just recently:
Started noticing a loss of power and inability to accelerate…. couple weeks later the car lost complete power on the road and stalled, I was able to turn it over to a very rough idle and feathered the gas to get it to a parking lot and get it towed.

Current symptoms:
1. Extreme vibrations and very rough idle and if it isn’t given gas it will stall. If kept around ~1000RPM it will fluctuate between 1k and 2k rpm’s. I can keep it roughly consistent at 2k RPMs.

Codes read:
1. Random/Multiple cylinder misfire
2. System too lean at idle bank 1
3. 02 sensor signal biased/stuck lean bank 1 sensor 1

So far I have:
1. Replaced coils and spark plugs
2. Cleaned throttle body
3. Screwdriver tested fuel injectors
4. Cleaned 02 sensor
5. Compression test (all around ~175)

Planning to:
1. Replace 02 sensor
2. Seafoam test

Looking for anyone that has had similar experience. The battery is not new and has not been disconnected recently. If anyone has any recommendations that would be greatly appreciated.

Update 1:
 

Found the issue ! Looking closer at the intake manifold the EGR valve burnt a hole through it! Assuming from carbon build up getting lit on fire. Does anyone know any prevention solutions?
https://cimg1.ibsrv.net/gimg/www.maz...0a75193fd.jpeg
https://cimg2.ibsrv.net/gimg/www.maz...9d5b3589b.jpeg

Update 2:
 

Replaced intake manifold and it fixed the idle issue. When driving I still have low power and won’t go above ~35-40mph.