And about 40k of that has been with longtubes. I don't get any codes, but sometimes when I take logs, they seem to be getting a little lazy.

Think it'd be worth the money replacing both of them now with new Bosch sensors, or just waiting till one of them takes a crap on me?

 

I replaced mine at 30k.... My truck only has 52k on it....

 

Leave well enough alone, on my 97 c1500 I have 130K on my stockers and it hasn't thrown a light. I get 20-21mpg out of my 4.3L 5 speed truck consistently. I'm leaving my shizzle alone unless it throws a light

 

Actually i think i have replaced mine twice, lol... The first time they were getting lazy. The second time was right before the warranty (1 year) was up on them, so i figured why not... Now, i don't even use them... NO trims for me

 

I just replaced mine at 155k with new Denso units (best ones you can buy) and there was no difference whatsoever.

 

That's the answer I was looking for haha

Although mine are a little lazy, I don't think it's gonna be worth the money to replace them just yet.

 

How do you like the speed density tune? More consistent power? Mine loves to run good with a new tune, but after some miles it gets shitty.

 

Are they turned off in your tune or are they on

 

Go SD, without a doubt.

 

How do they look as they warm up? Once they start moving, do they immediately hit their full range (0-900) or do they start oscillating by 50-100mv, then slowly work their way up to full oscillating range?