Lancer Fix 1 | Rough Idle, Engine Light, Oxygen O2 Sensors P0421 (DENSO Best)

Watch a better video here:    • Lancer Fix 32 | Car Refresh  
Lancer Fix Playlist https://bit.ly/2JQkmfC
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🌐 Website https://www.darkdragonwing.com
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0:00 Intro
0:13 Spark Plugs
0:21 Valve Cover Gasket
1:33 Air Flow Sensor
2:05 the Engine Being Unstable
2:13 IAC
3:01 O2 Sensors
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This is a blue 2003 Mitsubishi Lancer ES 2.0L 4G94 SOHC AUTO FWD.
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02-07 Lancer Upstream O2 Sensor DENSO https://ebay.to/2STKb3n
02-07 Lancer Downstream O2 Sensor DENSO https://ebay.to/3AzZ8sq
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In this video, the engine light was on before I clean the engine. The engine was having a rough idle and a lost of power. Without checking the engine light and I finally did in the end, I guessed many times. Here is what I had done:
1. I changed the spark plugs. How to -    • How to replace Spark Plugs on a Mitsu...  
2. I changed the valve cove gasket.
3. I cleaned the air flow sensor.
4. I cleaned the intake air control.
5. I changed the oxygen sensors. P0421
I finally found a fix.
( However you should clean the EGR too    • Lancer Fix 6 | Exhaust Gas Recirculat...   )

O2 sensors' rough idle: unstable idling, feel like a flood in the cylinders which gives no power when you try to accelerate it, seems to be fine once it's running for a while, happens every time when you start it up especially when it's cold...

Socket for the Lancer O2 sensors is 22mm or 7/8"
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Mods on this car:
*Red calipers, red drums
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