I made a quick search on this forum and couldn't find info on this problem. Apologies in advance if this is a repeat.

Working on my 2001 SSEi. Has about 120K on it. Recently noticed higher boost than normal and reduced fuel mileage. On harder accelerations, boost gauge indicates in the red. Need help to troubleshoot this. Can anyone point me in the right direction?

Most likely the weather has cooled down considerably where you are located. Colder air means denser and denser means more boost. This is normal. And unfortunately the more boost you have, the more fuel you need to burn with that air.

Thanks. I hadn't considered air density.

It didn't seem to have this condition previously in colder temps, however. My main concern is malfunction/damage to the supercharger and/or related components and I didn't want to ignore any early warning signs. Other than the boost indications, it seems to be running normally. I can hear more of a whine on acceleration since I replaced the stock air filter with a K&N. Other than that, it all looks good.

Any inspection or maintenance tips on this thing?

Thanks again.

superchargers are like wenkel engines.. they require very little.

Maybe give it an oil change (supercharger oil from GM only) every 30K or so. When it starts making odd noises somewhere around 100-200K miles, then it'* coupler and maybe bearing replacement time.

Thanks once again.