New 02 Sensors = Mileage Increase

[CJF]

Keep us posted on the mileage...

 

[voorland80]

Go Cary!

I'm a firm believer in changing these things out as scheduled maintenance (~100k) whether or not they're throwing codes. I've read up on them some lately, and mostly what I got out of it was that yes, they and their performance slowly and steadily deteriorate. And, unfortunately, their big flaw is that it's apparently very difficult to run an accurate diagnostic on them. (The FSM voltmeter(?) test is supposedly *not* very precise.) Plus they're $pendy.


They're such an essential part of the "closed loop" EFI operation that if they're old and you're having any mileage or smog problems, etc., seems to me you just oughta replace 'em.

Curtis

PS Paragraph 1 info was gleaned mostly from an article in a tech magazine for independent Mercedes Benz mechanics.

I'm goin' in.
On Lake Mead trip she gave me 16.5mpg. I thought, wow, that's my baby. Well, I have been driving LOTS of stop and go in town now, checked mpg recently and I about freaked, 6mpg! I thought I must be missing something, had figured it out wrong. But my receipts and mileage can't be lying. She doesn't cough and is running smooth, I don't understand. Is my foot that heavy? Does she think she's in Africa? Well, just the other night on the way back from Lowe's she flashed me a CEL for just a few seconds. It hasn't come back on. Can the two be connected? Would the code be stored so I can try and pull it? I need to get a FSM (I know, I know) so I'm thinking I will be giving highly recommended cruiserdan a call.
I'm goin' in.

"She's slow but sure, drinks like a drunk, but I love her still."

 

[CJF]

I think you can still pull the code, although you didn't state what year?

 

[voorland80]

oh, sorry. i don't have a real sig line yet. it's a '91 fj80, 3FE, 144k miles. i have some photos of it on my site. thanks!

 

[Nottajeep]

Just for technical history and input to this thread, my CEL was on with a P0125 reading. Replaced the front O2 with a new part from Cdan and wahlaa CEL is gone after the 2nd engine start. No ECU reset required (knocking on wood). I am still going to replace the rear O2 w/ 168k on it, just haven't decided if I'm gonna use the Denso OE I have on hand or reach out to Cdan again (firm believer in using Mr. T's parts only). Gas mileage is tbd at this point. I was getting 14mpg with the CEL.