[RipCity 2.5]

The car: 02 OBW 2.5 (auto) - 145k

At high RPMs my car makes this annoying sound. Its coming from underneath the car. It only happens when I'm really gassing it.

Of course, the good old P0420 CEL has been haunting me ever since I bought the car a year ago, and now its time for me to get my new tags and pass emissions. I had tried all the basic stuff to get rid of the code with no success, so both issues - The CEL and the noise - I suspected were a result of my catalytic converter (its a Walker Replacement converter the previous owner had installed). Ive heard that converters can whistle. I finally took it back to the shop it was done at, and they found it was failing and replaced the cat under warranty. That got rid of the CEL and I should pass emissions with flying colors. However, the sound still persists.

The car runs great, the sound is just annoying. Ill be getting my tranny serviced in a couple weeks. I really hope its not tranny-related, but we'll see. Could it be?

Anyone had a similar problem? Suggestions? Thanks all

 

[Braap]

Exhaust flange. 90% of us get it. More so if it's a salted area.

 

[cardoc]

Exhaust flange. 90% of us get it. More so if it's a salted area.

Dito.

Whistle is caused by vibration due to air movement. Like whistling through your lips. Any time you hear a high pitch whistle, look for an air leak either on the engine vacuum or exhaust including the EGR tube and its gaskets.

If its been going on for a while, and its on the exhaust, you will see the black marks from carbon exiting the leak. If its on the engine, you'll either have to listen really close to narrow it down or have the intake system "smoked".

Can you record it and post the recording?

 

[RipCity 2.5]

Definitely no salt up here in the NW, but you guys are right. The only other thing it could really be is exhaust related. Ill check for vac/exhaust leaks tomorrow.

Funny you mention "smoke" for the intake system - I was thinking of doing Seafoam this weekend. If its a leak, that should help me find it.

If all else fails, Ill try recording it

Thanks guys