O2 sensor which controls idle 360 98 ram

[joulian]

Hey I got a 98 2500 Ram that is loading up and slowly idling down till it eventually dies. Its also making a loud hissing noise as well while its loading up and sounds like it misses ( not because of ignition issue though ) ( I replaced the IAC and the TPS already btw long time ago )

I have it down to an 02 sensor , which one would control this perhaps? and why...

If I could get an opinion asap I have to pick wife up from airport tomorrow 1.5 hrs away and am trying to get it fixed today.

Thanks

 

[dodge dude94]

It would be the pre-cat O2 sensor, but I'll be honest, I've never heard of an O2 sensor controlling anything with the idle unless of course it's loading it up with fuel.

 

[joulian]

Update, it was the O2 sensor upstream....

I can't believe I have lived with this truck doing this for 5 years and $50 and 10 minutes of work fixed it.

I replaced it the other day and it hasn't loaded up nor idled down since. BUT its still a little rich , from what I smell with the exhaust.

Any opinions? Maybe put some new plugs in it since it was running so rich ? or replace the O2 sensor downstream as well?

 

[jsl6v8]

Ah, was going to say, I know auto zone here will run a test for free here and tell you exactly which sensor is bad.

 

[joulian]

it never popped up on scanner at Autozone. The dealership told me 2 years ago it was a leaky intake gasket.... they were happy to replace it for me for 1800.00. I said nope don't think so did it myself. Mad as hell after i started it up and it did it again. I thought my , how mad would i have been if I had paid them 1800.00 for it. Mind you I only paid 2200.00 for truck.

 

[dodge dude94]

Did you replace the pan or just the gasket?
If you replaced the plenum gasket it would be blown again. How's your MPG?