Before a tapping/knocking sound appeared, check engine light came on, the computer sent code P0420 - Catalytic converter failure. Please help me identify where this sound is coming from. This sound appears after the engine warms up. Is this noise from a fuel injector, exhaust manifold a valve? or coming from the interior of the engine? This van has been a good van with 173,500 miles. Please help me identify this sound. I have a video available where the noise is recorded.

 

Can tell you much without hearing it.

 

[Can I post the link for the video?

 

This is the link pf the video.

Thanks

 

Sounds like a clear cut valve to me or at least something in the top end. I'm no engine expert so wait for more opinions. You could try using a short length of hose cupped to your ear to narrow down the source.

 

I think cougar is right. Probably lifter noise.
Change your oil with a quart of ATF + 4 quart of regular oil in your engine. Sometimes it cleans out the lifter and makes it quieter.

your CEL have nothing to do with the noise, btw.

 

If the problem is a valve. Can this problem be fix and without an overhaul?

 

No. Would be easier/cheaper to install a used engine.

 

Atually, I think it is cheaper to rebuild this engine. Because on this Caravan, you can rebuild the engine with the block still in the car.

And you also get a "like new" engine. And used engine could do the same thing. The price could come out about the same or slight difference compare to install a used engine.

 

I would never in a million years rebuild an engine without hot tanking it.