The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 1991 GMC runs poorly after engine is warm

ChevyTech · 12-25-2006, 12:08 AM

Being it ran all that time with no check engine light, I think it’s a pretty sure bet there is an O2 senor on your truck.

All the information I checked shows the O2 sensor in the exhaust pipe in front of the catalytic converter for a 4.3 engine.

Here are some links you can check out.
Component location
http://www.autozone.com/servlet/UiBr...3d800870d8.jsp

O2 sensor information
http://www.autozone.com/servlet/UiBr...3d80086e71.jsp

12-25-2006, 12:08 AM	#6
ChevyTech Registered User Join Date: May 2004 Location: Minnesota Posts: 4,620	Re: 1991 GMC runs poorly after engine is warm Being it ran all that time with no check engine light, I think it’s a pretty sure bet there is an O2 senor on your truck. All the information I checked shows the O2 sensor in the exhaust pipe in front of the catalytic converter for a 4.3 engine. Here are some links you can check out. Component location http://www.autozone.com/servlet/UiBr...3d800870d8.jsp O2 sensor information http://www.autozone.com/servlet/UiBr...3d80086e71.jsp