I apologize ahead of time, if this has been discussed already, however I have looked, and not found anything about this exact problem. Several on here seem to have this problem when the car is cold, however mine is exactly the opposite.

Here we go, I have a 2000 Cadillac Seville STS. It has 125k on it. Purchased it in March, from some guy in Southern California. Shipped it to Michigan. It has never seen salt or corrosive elements. The vehicle sat for nearly five years, and from what I can tell, most or all of it was outside. The seller told me he could not pass those goofy emissions inspections, because of a "dirty sensor", so he just gave up on it.

I got the car here, and cleaned it up. amazingly, the OEM wheels are like new, and the body is decent, although several stone chips, no rust, no dents and only a couple small scratches.

Now, here is the problem, in detail:

After I drive the car for a period of time, I find that it runs rough, and once, it even stalled completely whilst stopping at a red robot. When the vehicle is cold, it idles fine. I am guessing that it is the result of some sort of restrictive air flow or something.

One of the nicest things I have found about the Cadillac, is the ability to read trouble codes from the display, without needing a code reader. Here are the codes, and the definitions I have found from here, hope they are accurate.

**the history codes keep repeating, I have checked codes three times, and cleared them.

Codes showing "CURRENT"
P1153- Heated 02 sensor (H02S), insufficient switching Bank 2 Sensor 1

History codes:
P-0171- Lean bank
P-0174- Lean bank
P-1599- Stall or near stall detected

Also have a B1341 Current, which I believe has to do with the HVAC. The aircon blows cold on drivers side, and blows HOT extremely on passenger side. It appears there is a door or something that is not closing or opening properly under the dash. If anyone knows exactly how to get to this to repair it, I would greatly appreciate it.

Thank you! Hope I have been descriptive enough, but not too long.

 

Gee, thanks for all the replies! NOT!

 

most likely cause would be a hole burnt thru boot between plenum and throttle body housing. Will set lean codes and can cause stall at idle, hole would be on under side / bottom - you won't be able to see it.