The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

rfmaster · 07-12-2011, 01:14 AM

BOSCH makes fine O2 sensors, but GM ECM PID algorithm does not match very well with BOSCH S curve. Most of the time it will work OK, but sometimes you get funny close loop cycling between rich -lean condition. When I switched from BOSCH to AFS-74 problem resolved itself. AFS-74 heated 3 wire O2 sensor was used in a 95 S10 4.3L V6 GM part number 25312179 or 19178959 or ACDelco AFS-74 (or 213-632).

Rock Auto has 19178959 (AFS74) for about $50

//RF

07-12-2011, 01:14 AM	#767
rfmaster Registered User Join Date: Oct 2003 Location: OC CA Posts: 1,374	Re: Tbi swap build thread BOSCH makes fine O2 sensors, but GM ECM PID algorithm does not match very well with BOSCH S curve. Most of the time it will work OK, but sometimes you get funny close loop cycling between rich -lean condition. When I switched from BOSCH to AFS-74 problem resolved itself. AFS-74 heated 3 wire O2 sensor was used in a 95 S10 4.3L V6 GM part number 25312179 or 19178959 or ACDelco AFS-74 (or 213-632). Rock Auto has 19178959 (AFS74) for about $50 //RF __________________ "The Beast" 1975 Chevrolet C20 longbed 350/700R4! with 3inch body lift Dual Flowmasters Super 40's! TBI retrofit completed (2007-07-29) New 383CID (+030) 08-304-8 9.5:1CR x36,005 (2012-12-17)