Gents,
Over the course of several months my SSEi's mileage has deteriorated -- now I'm at 21mph AVG babying on the highway where I use to be 26-31mpg on trips.
I scanned today and my O2B1S1 readings are ranging .7-.850 for EXTENDED periods (as in 5 seconds at times). This is a newer AC Delco 109 Design (the one in the box) and was replaced only a couple years ago.
No rough idle, stumbling, no poor performance, O2B2S2 is reading fairly constant after warmup (I changed it when I installed a hi flow converter). Just gas mileage sucks.
MAF gms/sec looks stable in the 6.3~ range at idle, calc load with A/C approx 2.3%.
I'm erring toward a bad o2 on this -- unless anyone else has any comments.
Poor Mileage / Bad o2?
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silverws6ta
- SLE Member
- Posts: 52
- Joined: Mon Jun 16, 2008 1:45 pm
- Year and Trim: 2000 - Bonneville SSEi
Poor Mileage / Bad o2?
2000 Bonneville SSEi - GXP Wheels, GM Aluminum Gaskets, 180*, AC 41-985's, AC Delco High Performance Wires, Double 'D' I-Shaft, Hogan 3" DP and Magnaflow CAT, Intense FWI, PCM, and 3.4 MPS, GB 715, Full Synthetics, LED Brake Light Conversion, Toshiba HIR's Low/High (one owner - was my moms car) 147k 11/10
2006 Cadillac STS-V - Stealth Gray - GM Performance Cat-Back Exhaust (Borla), D3 Cadillac Intake, Wait4Me E67 Tuned PCM, GM Accessories Smoke Taillights, 3rd Brake Light, Cross Drilled Brembo Rotors, 27k 11/10
2000 Trans Am WS6 - M6, SLP Lid & K&N, SLP Y-pipe, Borla Non-Adustable Exhaust (Sold the SLP); NGK TR55's, !TB, SLP Bellow, 180*, Taylor Thundervolt 10.5mm Wires, !CAGS, Custom Tuned PCM, Full Synthetics (mine from the day it was ordered )
2008 Escalade EXT - GMPP Intake, GMPP Performance Exhaust, Sport Grille, Chrome Tow Hooks, In Channel Ventshades, Front/Rear Matching Tint - 8k 11/10
2006 Cadillac STS-V - Stealth Gray - GM Performance Cat-Back Exhaust (Borla), D3 Cadillac Intake, Wait4Me E67 Tuned PCM, GM Accessories Smoke Taillights, 3rd Brake Light, Cross Drilled Brembo Rotors, 27k 11/10
2000 Trans Am WS6 - M6, SLP Lid & K&N, SLP Y-pipe, Borla Non-Adustable Exhaust (Sold the SLP); NGK TR55's, !TB, SLP Bellow, 180*, Taylor Thundervolt 10.5mm Wires, !CAGS, Custom Tuned PCM, Full Synthetics (mine from the day it was ordered )
2008 Escalade EXT - GMPP Intake, GMPP Performance Exhaust, Sport Grille, Chrome Tow Hooks, In Channel Ventshades, Front/Rear Matching Tint - 8k 11/10
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00Beast
- Retired Site Developer
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Re: Poor Mileage / Bad o2?
Definitely could be. How old are plugs, wires, air filter?
Ironically, I was just wondering to myself a few hours ago "I wonder what happened to the guy with the sweet STS-V on Pontiac Bonneville Club", lol. I guess now I know!
Ironically, I was just wondering to myself a few hours ago "I wonder what happened to the guy with the sweet STS-V on Pontiac Bonneville Club", lol. I guess now I know!
Bye Bye:
RIP sandrock
RIP sandrock
Sirius wrote:Think about it. You’re tooling down the road in your Prius, knowing full-well that this thing being green is as big a sham as federally mandated ethanol-enriched gas, Russia pulling out of Ukraine, and Obamacare.
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silverws6ta
- SLE Member
- Posts: 52
- Joined: Mon Jun 16, 2008 1:45 pm
- Year and Trim: 2000 - Bonneville SSEi
Re: Poor Mileage / Bad o2?
Plugs has probably 10k on them.. the wires maybe 30k --
But yep it was a bad O2; which also was about brand new. It was the one in the 'box' which I think is the new P/N manufactured by Denso -- it went bad over a course of 2 years and 30k miles; I put the ORIGINAL o2 sensor back in it that had over 100k on it and it was running smoother and the rich/lean reading were alternating much faster with it. Fortunately I had one of the original AC-Delco AFS-109's brand new in a bag i found in my stash and installed yesterday, and while I was at it cleaned the MAF -- This morning my mileage increased even more and I'm not having to go 1/4 throttle to get the car to move now. Its back to just light acceleration and smooth under load.
Lol! Yep I'm still around -- I fell off for a while but I'm back!
But yep it was a bad O2; which also was about brand new. It was the one in the 'box' which I think is the new P/N manufactured by Denso -- it went bad over a course of 2 years and 30k miles; I put the ORIGINAL o2 sensor back in it that had over 100k on it and it was running smoother and the rich/lean reading were alternating much faster with it. Fortunately I had one of the original AC-Delco AFS-109's brand new in a bag i found in my stash and installed yesterday, and while I was at it cleaned the MAF -- This morning my mileage increased even more and I'm not having to go 1/4 throttle to get the car to move now. Its back to just light acceleration and smooth under load.
Lol! Yep I'm still around -- I fell off for a while but I'm back!
2000 Bonneville SSEi - GXP Wheels, GM Aluminum Gaskets, 180*, AC 41-985's, AC Delco High Performance Wires, Double 'D' I-Shaft, Hogan 3" DP and Magnaflow CAT, Intense FWI, PCM, and 3.4 MPS, GB 715, Full Synthetics, LED Brake Light Conversion, Toshiba HIR's Low/High (one owner - was my moms car) 147k 11/10
2006 Cadillac STS-V - Stealth Gray - GM Performance Cat-Back Exhaust (Borla), D3 Cadillac Intake, Wait4Me E67 Tuned PCM, GM Accessories Smoke Taillights, 3rd Brake Light, Cross Drilled Brembo Rotors, 27k 11/10
2000 Trans Am WS6 - M6, SLP Lid & K&N, SLP Y-pipe, Borla Non-Adustable Exhaust (Sold the SLP); NGK TR55's, !TB, SLP Bellow, 180*, Taylor Thundervolt 10.5mm Wires, !CAGS, Custom Tuned PCM, Full Synthetics (mine from the day it was ordered )
2008 Escalade EXT - GMPP Intake, GMPP Performance Exhaust, Sport Grille, Chrome Tow Hooks, In Channel Ventshades, Front/Rear Matching Tint - 8k 11/10
2006 Cadillac STS-V - Stealth Gray - GM Performance Cat-Back Exhaust (Borla), D3 Cadillac Intake, Wait4Me E67 Tuned PCM, GM Accessories Smoke Taillights, 3rd Brake Light, Cross Drilled Brembo Rotors, 27k 11/10
2000 Trans Am WS6 - M6, SLP Lid & K&N, SLP Y-pipe, Borla Non-Adustable Exhaust (Sold the SLP); NGK TR55's, !TB, SLP Bellow, 180*, Taylor Thundervolt 10.5mm Wires, !CAGS, Custom Tuned PCM, Full Synthetics (mine from the day it was ordered )
2008 Escalade EXT - GMPP Intake, GMPP Performance Exhaust, Sport Grille, Chrome Tow Hooks, In Channel Ventshades, Front/Rear Matching Tint - 8k 11/10