'95 DeVille - P046 Code

[GailyBedight]

Recently purchased a 95 DeVille, (4.9 L), for my daughter. After about 800 miles, she put in a tankful of regular gas, and within 50 miles got a service engine soon light and threw two codes:

P013 - Right O2 sensor not ready - History
P046 - Right to Left Bank fueling difference - Current

Any suggestions what this might be and how to go about troubleshooting this? The other threads I've seen don't offer much. We're going to put in premium when we get down to about 1/2 a tank.

Thanks for any help you might give!

[Ranger]

P013 - O2 sensor might be getting a little lazy in its old age. If it persists, you may need to R & R it.

P046 - Not really sure , but I'd start by looking for a vacuum leak. See if anyone else agrees or has any better ideas.

[deville555]

I looked up what it means and possible causes are faulty injectors on one side of the engine, cracked or fouled spark plugs, or exhaust or intake manifold leak
I also found this for the P046 code
http://www.cadillacforums.com/forums...um/t-5760.html

[GailyBedight]

Thanks for the help guys! With 103K on the clock, I suspect that there will be some R & R of parts required down the road. I think I'm going to start with the O2 sensor, then a tune up, and when I get under the hood look for the obvious, vacuum leaks, etc. I'll let you know how I make out. I think the kicker is the first code about the O2 sensor, but we'll see.

Thanks again.