So while driving home from rescuing the T/A after the starter konked in a gas station, had to walk to get The Limo and jump the Bird to get it back to the bodyguy's house. Unrelated, really, but when I was driving home, with Carl, the SES light on The Limo randomly came on, and nothing about the car changed. I scanned it when I got home and it was P0420, specifically the picture below. I was perplexed since I have a ZZP emulator on the rear O2 Sensor. What could cause this? Could my Emulator be kaput? I'm confuzzled...any help is appreciated.
EDIT: I might add I cleared the code but it came on about ten minutes later on my way to work...

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

I hate that code. What is the status of your front O2 sensor?

_________________


2009 Ford Flex 63K[/u] My DD & super utilitarian vehicle that we call the White Bus.
2006 Honda Accord EX V6 Coupe 73k; Wife's hot rod & highway ride.
SOLD: 2002 Bonneville SLE; 230K, Mods: Solid hockey puck front mount, Intense FWI intake, 180 degree thermostat, Magna Flow high-flow cat, ZZP O2 emulator: Nothing major but maintenance and what it takes to keep the dash lights off and the mileage up..
2004 Bonneville SLE 201k, Pearl White (Old man's ride)

Replaced maybe 4-5k miles ago...

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

Sounds like your emulator died. Call ZZP.

_________________
Bye Bye:

RIP sandrock

Will do first thing in the morning. Hoping this is what it is.

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

Ran into the same things on my daughter's Regal. Had a high flow cat on it that kept throwing the code. The ZZP emulator lasted maybe a couple of years, before it had to be replaced.

_________________
*Gone, but not forgotten* - Black 2000 SSEi, HIR Headlights, Angel Eyes fogs, 3rd brake light overlay, hi-flo cat, 180 degree thermostat, HS 1.9 rockers, LSx yellow springs, Intense FWI, PCM, shift kit, push rods, and 3.4 Pulley. ZZP Power Log.

Couple of years would be nice! I've had mine for maybe four or five months!

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

I get the same code periodically with a Magnaflow cat on the car (weld on)...rather annoying.

I'm curious if an aftermarket rear O2 will fix the issue (non-gm).

No, the rear O2's just report to the PCM, they should all read the same. The best way is to get it tuned out, second best is to use the emulator, if it doesn't fail, lol...

_________________
Bye Bye:

RIP sandrock

I think Im going to have Kyle turn that code off in spring when he does my tune on second thought, this is annoying...lol Called ZZP,they do tech support on a callback basis, so Im awaiting a call back.

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

Wouldn't you know it...I ordered a new emulator this morning from ZZP and about 20 miles ago, the SES light just went away... IDK, but it works for me, so I won't ask questions. Lol
Maybe it got scared because I went to the Buick dealer to sneak a look at the new Regal again, and to see if the GS came in yet, sadly, it has not...lol

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily

ZZP's "tech support" is more of a "When I get around to it and feel like it" more than anything...

_________________
Bye Bye:

RIP sandrock

They were no help to me at all...

_________________
Will
88 Cutlass Ciera Brougham International | 120k mi | White w/ Dk Claret Int. | Roller to be S2 L67/4T65E-HD | 1 of ~5100 3.8 FE3 Int'l series
91 Riviera | S2 L67 Swap/4T60E | 127K mi | Antelope Met. w/ Tan Int. | Saved From Death By Crusher
92 Bonneville SSE | L67/4T60E | 77K mi | Med Slate Grey w/ Two-Tone Grey Int. | Low Miles Time Capsule
92 Lumina Z34 | LQ1/4T60E | 177k mi | Torch Red w/Grey Int. | Rusty In Odd Spots
99 Tahoe LT | L31/4L65E | 276k mi | Spiral Grey Metallic w/Grey Int. | Truck for Truck Things and Portable Concert Hall
03 Park Avenue Ultra | 212K mi | White Diamond Met. w/ Shale Int. | Southern Time Capsule
05 Acura RL | 155K mi | Carbon Grey Pearl w/Ebony Int. | The Super-Hooptie Daily