Check Engine Light - Code P0420
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Year: 2000
Model: Cherokee
Engine: 4.0L
Check Engine Light - Code P0420
Hey guys, I have been trying to pinpoint this for a while now.
It reads as follows:
Catalyst efficiency below threshold -Bank 1
-Large Vacuum Leak
-Rich AF ratio - fuel system faulty
-Ignition system malfunction
-Faulty Catalytic converter
Troublshouting
-Catalytic converter defective
-Engine misfire or running condition
-Large vacuum leak
-Engine oil leakage into exhaust
Now, I found a vacuum leak, it was one of the lines connected to the cruise control, it was completley broken in half. Fixed that. Disconnected battery, check engine light came back on after about 100mi.
Engine seemed/seems a but sluggish, so I did a tune up. New boots and plugs. The old ones were probably original with 91K on them. The plugs were junk, I'm surprised it ran fine.
There is also a buildup of soot around the outside of the tail-pipe and the engine feels a little sluggish still, but is definetly better after the tune-up.
What would you guys do? I'm going to look for more vacuum leaks tonight, but I doubt I'll find any.
It reads as follows:
Catalyst efficiency below threshold -Bank 1
-Large Vacuum Leak
-Rich AF ratio - fuel system faulty
-Ignition system malfunction
-Faulty Catalytic converter
Troublshouting
-Catalytic converter defective
-Engine misfire or running condition
-Large vacuum leak
-Engine oil leakage into exhaust
Now, I found a vacuum leak, it was one of the lines connected to the cruise control, it was completley broken in half. Fixed that. Disconnected battery, check engine light came back on after about 100mi.
Engine seemed/seems a but sluggish, so I did a tune up. New boots and plugs. The old ones were probably original with 91K on them. The plugs were junk, I'm surprised it ran fine.
There is also a buildup of soot around the outside of the tail-pipe and the engine feels a little sluggish still, but is definetly better after the tune-up.
What would you guys do? I'm going to look for more vacuum leaks tonight, but I doubt I'll find any.
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