Unknown 2000 LS v8 problems

[2000mnLSV8]

I own a 2000 ls v8 with approximately 150,000 miles. Ever since i bought it from the dealership about 4 months ago i have been plagued with issues. First i had the front tranny pump seal replaced because it started leaking, and then i replaced the plugs and coils. Now i have encountered an odd issue with the engine making odd noise from 1500 RPMs to 600 RPMs at idle and moving. When it is in that range it makes an odd grinding kind of noise which seems to be coming from the rear passengers side of the engine, it is even easier to hear under the car. The car will still drive ok and does not surge or anything, but there is a slight loss of power in that RPM range. Along with that my engine light comes on, i ran a diagnostic on it and it turned out to be the PO133 o2 sensor ckt slow response (bank 1 sensor 1) keeps tripping from it. I talked to my friends dad who is a mechanic and he suggested that it could be a vacuum leak. Overall i am just unsure of what to replace because even he wasn't sure if it was a vacuum problem, and i don't want to start pouring money into the car to replace things that could be causing it. Any suggestions on what could possibly be causing it and even how to fix this problem are appreciated!

 

[joegr]

Do you mean 600 to 1,500 RPM, or did you really mean 1,500 to 6,000 RPM?

Does "at idle and moving" really mean that the noise is there while stationary and while moving?

 

[LS4me]

Replace both forward (of the cat) O2 sensors. If nothing else, it's time.

 

[2000mnLSV8]

yeah might have too, and its from 600 RPMs to 1,500 RPMs, it does it while idling and while moving, but only in that RPM range

 

[joegr]

yeah might have too, and its from 600 RPMs to 1,500 RPMs, it does it while idling and while moving, but only in that RPM range

Check all the exhaust hangers. Maybe one of them wasn't put back on right and is rattling. Look for exhaust leaks too, an exhaust leak could cause the slow O2 code.

You could have a nearly clogged catalytic converter.

Your torque converter may have a problem.

...

 

[2000mnLSV8]

yeah that could definitely be it, i will check that out for sure! thank you for the suggestion.