I have an '04 TSX. Already had the engine replaced at 120,000 miles when a timing chain tensioner failed and the engine went out of time. Replaced with an engine that had around 40,000 miles. Drives great...but about a week ago a check engine code P0420 was illuminated. Mechanic thinks it's the catalytic converter...which makes sense because I'm at 140,000 miles, and there is a rattling/chirping noise coming from the cat converter.

While I was looking around the car, also identified a ticking engine noise that can only be heard when the hood is raised. It's concerning, because I've already had engine issues once. The surpentine belt looks old...maybe a slight squeel...but the clicking is definitely coming from the engine.

Any ideas? Is the P0420 code in anyway related?

 

I'm havin the same problem rite now.....wonder if it has somethin to do with the valve clearance..hmmmm...

P.S. mine only has 81k on it...

 

I've read that both the AC compressor and/or the fuel injection can be responsible for the clicking noise. Or..... it could be valvetrain noise. As long as the car runs fine and the noise isn't too objectionable, I'd say live with it (I do!).

 

It seems like it gets louder when its cold outside...

 

I only notice a ticking noise with the hood open. I briefly tried to pin point the source with a stetoscope but couldnt locate it.