P0420 Generic - Catalyst System Efficiency Below Threshold (Bank 1)
Freeze Frame Data
Fuel Sys 1 - CL................Don't worry About it
Fuel Sys 2 - CL................Don't Worry About It
Calc Load (%) - 9.41........When the 'Cel' came on, You were Almost Throttle Closed
ECT(*C) - 85....................Engine Coolant Temp was 85 Dec C..Normal running Temp
STFT B1(%) - -1.56..........Short Term Fuel Trim was pulling a Little Fuel (-)
LTFT B1(%) - -3.13...........Long Term Fuel Trim has Figured you need -3.13% of Normal Fuel
STFT B2(%) - -1.56..........Short Term for the Other Fuel Bank is -1,56% Pulling a Little Fuel
LTFT B2(%) - -2.34...........Long Term Fuel Trim for the Other Bank has Settles on -2.34% Fueling Correction
Eng RPM - 3414.................RPM when the Cel Came On was 3414
Veh Speed(km/h) - 103......103 KPH when the Cell Came on
IAT(*C) - 26......................you were sucking 25 Dec C Air ..
Throttle was almost Closed and you were travling about 70 MPH when the Cel Came On
The ECU and the O2 Sensors are Playing very Nice with each Other, by looking at your Fuel Trims.. The Long Term Corrections and the Short Term Corrections are VERRY NICE!.. Same Direction and Less then 5 total.. your car is behaving it self very nicely
Your 420 code is likely caused by an Exhaust Leak.. and by looking at the Fuel Trims.. it's not at the Head to Manifold Joint.. as the Long and Short Fuel Trims would not be so Even if the Leak was at the Head, As the O2 Sensors would be 'Sniffing' Free O2 From the Exhaust Leak..
This leaves the Donuts at the Three Amigos or a Crack in the Pipe AFTER the two Main O2 Sensors..
You can Pressurize the exhaust pipe with a Shop Vac Hooked to Blow.. then you can crawl around the COLD exhaust pipe looking for the Leak..
The Previous Owner did you a Favor by Gutting the Pre-Cats. And the Exhaust Shop just helped to perpetuate the inaccurate Information that the Pre-Cats are necessary for the Main cat and the Final O2 Sensor to Work Properly.. They are Not.. The Pre-Cats are just Little Cats that heat up sooner.. ( By a Few Minutes ).. and get the Car 'Cleaner Sooner' than without.. The O2 Sensors ( 3 Of Them ) will not know if the Pre-Cats are Gone.. as the First Two are Before the Pre-Cats, There fore the Pre-Cats will not Affect them.. and the Last O2 Sensor is after the Last Cat.. So it's still after the Only Working Cat.
IF the Spyder had an O2 'Air Injection System' BETWEEN the Pre-Cats and the Main Cat ( Some Cars to for Nox Reduction ), then things would be Different.. But That is not the Case Here.. Pre-Cat Removal will just Save your Engine. Your Car will no Have an 'Exhaust Profile' of a Celica GT.. they use 1ZZ Engines and No Pre-Cats.. So By Gutting the Pre-Cats your engine will now live about as long. and pollute like, a '00 Toyota Celica GT
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