Reading Spark Plugs

AjRagno

TJ Enthusiast
Supporting Member
Joined
Dec 27, 2019
Messages
638
Location
US
2005 LJ/250,000 Miles

Could I get some feedback on the condition of these plugs and how they may reflect on the condition of the engine? I've been getting a lean code on bank 2 (P0298) since spring but can't find an intake or exhaust leak so I'm not sure if it's running lean or not. I haven't noticed any drivability issues. Gas mileage is normal, engine is smooth and has plenty of power.

Conditions for the code are always the same. I drive around town all week without any issue but when I take trips on the weekend, after the first stop for gas or food, when I get back up to speed on the highway the MIL comes on and I get P2098.

These are NGK ZFR5N plugs after 30,000 miles, with a lean code for bank 2 for last 10,000 miles.

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Not bad looking plugs for a Waste Spark system...

How old are the O2 sensors ?
IF you have a scan tool you can check the O2 sensor voltages (.1-.9 VDC) generated real time to see what the other O2 sensors are seeing; .1-.3 VDC would be considered LEAN.
 
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