2001 GTP; Couple of issues...

I get a constant whining noise from the supercharger. When I had my exhaust done they told me the bearings were probably going. The whining is heard most when I'm at a stop or the car is parked with the engine running.

The resonator on my exhaust had a huge leak and instead of replacing it I had a piece of straight pipe welded in. I also replaced the cat. conv. with an aftermarket one. Now every other trip I take to work I get a DTC p1133 (insuficient switch?). I have an Auto Xray that I use to clear the code. Is it a bad O2 sensor? My car does have 181K miles...

Thanks in advance for any insight.

The whining noise you speak of is probably one of the tensioner pulleys going bad. While the supercharger can whine and the bearings do wear out I would check the tensioners first. They are much cheaper and easier to replace. Also make sure the oil in your supercharger is up to the proper level. Low oil can cause the bearings to wear prematurely and if you have never changed the oil you are certainly due. As for the code it is possible that the aftermarket cat is causing the problems but I would replace the rear sensor first. Bad sensors can cause a lot of issues and check engine lights.

P1133 is for insufficient switching on the O2 sensor before the cat, a lean or rich condition could cause this, as well as a contaminated sensor......since you have a scan tool watch the sensor, especially the cross counts....

As for the whining, as GTP Dad said, it could be the tensioner, P/S pump. alternator, transmission, etc., that could be causing the whining.....a mechanic's stethescope should be able to narrow it down.....

Normally, I would say remove the belt and see if the noise is gone.....then rotate each pulley, looking for the noise.....but in your case you have two belts and they are a pain in the butt to remove.....

The whining noise you speak of is probably one of the tensioner pulleys going bad. While the supercharger can whine and the bearings do wear out I would check the tensioners first. They are much cheaper and easier to replace. Also make sure the oil in your supercharger is up to the proper level. Low oil can cause the bearings to wear prematurely and if you have never changed the oil you are certainly due. As for the code it is possible that the aftermarket cat is causing the problems but I would replace the rear sensor first. Bad sensors can cause a lot of issues and check engine lights.

The rear sensor, is this an upstream or downstream sensor? I want to make sure I get the right one.

The one AFTER the cat is the downstream.....the one between the ex manifold and BEFORE the cat is the upstream one......this is the one causing P1133.....