88 bronco with the v8 (5.0L) and my question about a code that is spitting out and a noise. i think they might be related though. the code syas that the catlyst efficiency low-bank2. the oxygen sensors monitor the catalytic converters ability to store oxygen. one cause is the cat is bad which could be caused by engine missfire or large vaccum leak, or oil leadking into the exhaust valve guide seals, piston rings. all of this infromation is from autozone spitting codes and information at me.

the noise happens the most around 25-35 mph, and over rough surfaces, which i thought something may be in the suspension, but when i'm parked i push up and down on it, and it doesnt make any noise. so im thinkin somethin could be lose in the cat. any thoughts?

(p.s. i would like to stay legal, i.e. no cutting off the cat)

right now im driving to check the gas mileage to see if that has changed any so thats my thoughts as of now.

 

First off, check the heat shield on the cat. They tend to rust at the spot welds that hold them on and rattle.

 

ill double check the heat shield, but i did get up under it and hit on the cat and i didnt hear anything rattle, which is kinda weird, and i revd the motor in idle and nothing rattled. so any other ideas?