Mine are rattling pretty bad. What kind of adverse effects can this have other than being bothersome? Could it give faulty O2 readings?

 

Usually means, it's going bad, and may clog up soon. I'd replace it with a hi flo one.

 

I just want to know if its what is causing my idle problems.

I have cleaned the IAC, I have checked the TPS, everything should be fine.

Except my idle is a little erratic, dips low sometimes and makes the car shake before it surges back up, and sometimes dies when going into gear.

Also I get an intermittent code 43.

Argh.

 

One time my GFs 96 Blazer's idle would dip a little low when coming to a stop, I guess if it got worse may have stalled. Tookk it to a dealer and it was a bad cat.