The engine stalls sometimes when I come to a stop or slow down. Ive noticed the rpm hanging around 450. It idles fine when in park or neutral.

I do know that I have a bad oxygen sensor. Could this be the cause? Is there any way to increase my idle rpm?

 

It sounds as though your EGR valve is clogged and not closing at idle, as result the fuel mixture becomes too lean and your engine dies.

 

It sounds as though your EGR valve is clogged and not closing at idle, as result the fuel mixture becomes too lean and your engine dies.

It could also be a vaccuum leak on the intake.

 

A bad 02 sensor will send too much fuel into the engine, causing all kinds of sputtering and an overly rich condition. Is there any black smoke out the tail pipe when this happens? Don't overlook the the EGR system too, like AJ said. Good luck,,,,98