I was consistently getting P0171 lean condition codes on my 2003 XKR.

Finally, had a local shop do a smoke test. The test indicated a large vacuum
leak under the supercharger and/or plenum area. Lots of smoke.

What villains reside in this area that could be spawning this leak?

Is it likely that the supercharger will have to be removed to address this
issue?

If the supercharger will have to be removed, what other parts, hoses
gaskets should be replaced at the same time?

I've been on the forum for some time, and I realize that this is huge
request, but, any guidance or thoughts would be greatly appreciated.

 

I don't *think* there is anything *under* the supercharger that could leak.

But, the duct seals between the "V8" top part of the supercharger and the
twin ducts leading to the throttle body can get deformed and sucked in.

If it was the bottom part of the seal, it might appear to come from underneath.

Waiting for corrections from others

 

The supercharger duct seal problem did extend into 2003...check your VIN number against the TSB: http://jagrepair.com/images/TSB/TSB2...erformance.pdf

 

Is the EGR around there?

May be room for a borescope?

 

As other said, nothing is actually under the supercharger. Did it appear to come from one side or the other in particular?

There is a small injector manifold between the intercooler and heads. Those have something that look like a small head gasket on either side, plus the injector o-ring, all of which could leak.

Intake elbow at the rear of the supercharger is another possibility. The EGR is at the far rear near the firewall, plus numerous sensors and vacuum connections for brakes, breather, on the left and right sides.

Something down in that area seems more likely to me than the injector manifold gaskets. And if they did the test with the intake tube on, it would be difficult to see most of those vacuum ports on the elbow.

 

under my plenum on my 03 non XKR XK8 there is a vac line that runs from fuel regulator to the TB if I recall correctly.