Exhaust help

Hi guys, new here, and also not that mechanical. My truck - 1991 pickup-SR5 - 4WD. Exhaust just got REAL loud, and the exhaust was replaced about 6 months ago. Decided to take a look under myself and this is what I found. Can anyone help me?

Thanks in advance!
Scott

http://www.oceansedgewebdesign.com/temp/exhaust.jpg

O2 sensor is hanging loose. If it fell out, there will be a hole in your exhaust system causing a lot of noise and an exhaust leak. Does your truck have an air pump? I noticed a pinched off air intake on the catalytic converter.

Thanks for the reply! I am not sure about an air pump but I saw that as well. Is it a big deal to put the O2 sensor back or do I need to have it done?

Thanks again

You just need a new O2 sensor gasket, and then bolt it back in palce. I would just replace the old sensor though. It looks used up anyway. A new one would give a little bit better gas mileage too.

Thanks, awesome info!

Appreciate it guys.

No big deal provided whatever holds the sensor to the exhaust pipe is still there (studs, captive nuts, etc.). Use a little anti-sieze on the threads when you install it.

So, is it determined that the bolts rusted? or maybe fell out? I can't imagine that if it was left loose on accident by whoever worked on it, that o2 sensor would hang out over the hole for 6 months without making a sound up until now.

They were rusted. I brought them back to the guy who did the exhaust and he fixed it up for me.

Thanks again to everyone in here for the help.