2001 SSEi - 84,000 miles

74000 miles Replaced rear O2 sensor
84000 - Replaced Catalytic Converter
84000 - replaced upper O2 sensor

only use sunoco 93 gas(maybe a 92 here and there)
(occasionally use a Lucas bottle/ maybe 1x a year, car ave. 5000mi per year)

P00420 would go off maybe every 1500 miles or so
now, every 120 miles now she puts out the P0420 code

symptoms (only because im really looking due to light)
when under load (climbing a hill) and if RPMs are around 1200 she sounds like shes struggling, like i have to give it a lot of gas, soon as i press on gas she goes
gas mileage is about 15.8 in town

will update if i see more

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some info for you in between code resets

http://www.easterncatalytic.com/educati ... 420-codes/

https://www.obd-codes.com/p0420

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poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

What cat did you put in?

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

I don't know, I paid to have someone do it and they ordered the part.
I took it to my regular mechanic to have things assessed.
He said looks like an aftermarket "performance" cat was used. The code is most likely due to the cat.
He suggested eiter remove this one and put on a OEM replacement, or buy a tuner and ignore the P0420 code. (as well as enjoy other benefits of tuner)

He said the current cat is not harming the car.

feedback?

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what?, the guy who installed it doesnt know what he installed - call him and get the order reciept/invoice. you need a 50 state legal cat or the cali/Canadian one to avoid issues

no I dont believe that any harm will be done , but, you're not going to pass emissions with the code

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poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

If necessary, you could go the route of an emulator.
https://zzperformance.com/3800/o2-emulator

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*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.

Since it struggles up hills, it makes me think you have some kind of ignition system issue. Is there any other indication of troubles? Does it feel good when you're WOT?

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-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

You need a name brand Heavy Metal catalysis, he probably put in a cheap Chinese piece of junk and charged you for a good one.

I recommend the Magnaflow 99306HM (around $100 online), I install them on all my project cars, never had them throw a code.

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 55k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 95k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 260k | Official Bonneville Hauler

Thanks for the recommendation.

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I have had ignition problems cause a P0420 before.
With your mileage, if your plug wires are original you may want to consider changing them and also check plug gaps.

at 60000miles i had new plugs wires done

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