Engine code 33

[allsierra123]

I was trouble shooting a squeal/screech today. It kicks in a 3000 RPM as soon as the rpm's drop IE the tranny shift or I let off the throttle the noise stops. It does it in park or neutral the same as driving. I was unable to isolate it. But when the hood up its pretty loud and high pitched enough to hurt your ears. Then all of the sudden I got a random check engine light. I took it down had them scan it and got a engine code 33 something about the egr valve or low vacuum. Has anyone else had this happen are the two symptoms related or do I have two very different problems?

95 yukon 6.5

[allsierra123]

Update code was gone today no light and it showed nothing in the scanner. Still have the screech going to pull the belt to isolate it.

Sent from my SGH-T679 using Tapatalk 2

[allsierra123]

Update new belt no screech. Gotta test drive and see if the code comes back.

Sent from my SGH-T679 using Tapatalk 2

[vegaman04]

The 6.5l's are know for the vacuum pumps locking up, check into that.

[allsierra123]

It wasn't locked up. Im guessing the belt was slipping.


Sent from my SGH-T679 using Tapatalk 2