: what to do with a code

05-19-08, 07:46 PM
:worship:does anyone know why a rear bank running lean code would be thrown and what the fix would be? Thanks:worship:

05-19-08, 08:01 PM
The code would be thrown because the bank is running lean. A common cause would be a vacuum leak in the intake system. With the engine running, spray starting fluid around the engine. When the engine speed changes you're in the right area. Be careful because it takes a while for your hair and eyebrows to grow back out.

05-19-08, 08:06 PM
Add the model and year to your profile so we know what we are talking about.

05-19-08, 09:26 PM
2001 Eldorado vinY

05-19-08, 10:05 PM
Check for a vacuum leak in the "plenum". on the 2000+ Northstars, the plenum is the rubber coupler between the TB and the manifold. They seem to be a rather common problem. They usually split on the bottom where it is unseen, but spraying some Brakleen around it will usually increase the RPM, a dead giveaway of a vacuum leak. Do a search for plenum.

05-19-08, 11:10 PM
come on guys
This car has an AIR pump.
The AIR system has a valve that can leak air into the exhaust before the O2 sensor. This can set a lean code

05-20-08, 09:30 AM
Thanks AJ that makes more sense than a vacuum leak in the intake. Your the man.

05-20-08, 11:36 AM
Thanks AJ that makes more sense than a vacuum leak in the intake. Your the man.

Vacuum leak is the #1 reason for this code.
The leaky AIR valve maybe #2 or further down the list

05-21-08, 09:02 PM
This car is for sale at a used car lot, with 145,000 miles on it. Very nice Florida car no rust no external leaks nice inside and out. The owner doesnt want to repair the code and said he will wholesale it out. He wanted $3995 for the car. I have worked on obd1 cars before and think I could probably fix this fault with some trial and error. Does anyone have an opinion if this car can be fixed reasonable and what should I offer him for the car? Thanks John

05-21-08, 10:56 PM
As a couple of people have suggested, find the vacuum leak, then do a parts search in one or more of the recommended sites in these Forums. Find the fixes and workarounds for each of the vacuum code causes discussed at great lengths in here and Seville/Eldorado. Do a Kelley Blue Book search and come up with your best guess of overall condition and go from there.

You may also find that there are a considerable number of members who have tracked down the same symptoms you describe.

On the car you describe, the intake-to-throttlebody rubber plenum (bellows connector) is a prime suspect in a vacuum leak hunt. As AJ clarifies, the A.I.R. valve leak is somewhat more down the order of faults possible......

The parts necessary will cost you around $70 online, plus a couple of hours of your time. Hand tools. patience. experience.

05-22-08, 08:19 AM
Thanks submariner, thats exactly the answer i needed.