2000 Ecsb W/ 5.3 110k Miles

[rjirvine]

My 2000 Silverado 4x4 ECSB w/ 5.3 has 110k miles on it. I have Michelin LTX M/S LT 265/75R16's on it. Should I change my original 02 sensors? I'm thinging Bosch? I get about 13 MPG city and 16.95 Highway. I'm not throwing any codes, but heard the sensors get "lazy" as they get old. I want to maximize my gas mileage with current prices of course. I'm thinking of changing the ones before the cats and leaving the after cat ones alone. Any advice?

[98 Z71 SLT]

Alot of guys will tell you differently, but why throw good parts away??

 

Just because the O2's have over 100k on them means NOTHING.

 

GM designed your PCM and Programming to actually DETECT a lazy sensor, and then trigger SES light

 

Just leave it alone. If you actually had a bad/lazy O2, your PCM will gladly warn you...

[svensk]

Alot of guys will tell you differently, but why throw good parts away??

 

Just because the O2's have over 100k on them means NOTHING.

 

GM designed your PCM and Programming to actually DETECT a lazy sensor, and then trigger SES light

 

Just leave it alone. If you actually had a bad/lazy O2, your PCM will gladly warn you...

I dunno mine was a steady decline in mileage and power and then it started throwing codes. I replaced mine with Bosch ones from NAPA. Was around 115-120K when they went out.