/o/ im in dire need of your help
So i bought a 1999 accord without a catalytic converter and the CEL is on, but its wasting MASSIVE gas, im getting about 10MPGs, exhaust pipe is full of black soot and in morning startups it smell like a weird sort of gasoline like smell
I took it to the shop but the stupid mechanic told me its wasting gas cause it doesnt have a cat and to take it to a mufflers shop. So i took it there and the guy at the mufflers told me the cat wont do anything to improve MPGs and that it was probably one of the two o2 sensors.
What should I do /o/? Check engine code is p0420 "low efficiency threshold in the catalytic converter". Im pretty broke so i dont know if i should just replace the o2 sensor on the front (or the back) since theyrE about 60 bucks each
Your car has two o2 sensors, one before the cat and one after. It likely uses the one after the cat to measure how much catalysis actually happens. Since you don't have a cat, no catalysis happens and your ecu is confused as fuck.
As to why your ecu would dump mad fuel in response to having to cat, I'm as lost as you are.
If your o2 sensors are the unheated type, they're both probably fucked from the overly rich condition. Your spark plugs are also probably fouled or on the way to being fouled.
You can either get a new cat and possibly new o2 sensors (and probably spark plugs too but they're cheap), or you can replace the o2 sensors with resistors to fool the ecu. I'm not sure how to do that on your particular vehicle and I would only recommend it as an interim solution. You would lose any fuel/air ratio correcting ability and you would certainly fail an emissions test if you used the 2nd solution.
Look for a cat first and o2 sensors later. Your check engine error indicates that the car knows you are missing a cat, so no amount of o2 sensor replacement will fix that particular error. Your o2 sensors may be fucked anyway as a side effect of the richness though.
>>14128730
This anon seems like he's not a complete idiot.
>>14128624
>So i bought a 1999 accord without a catalytic converter and the CEL is on
You're a moron. Get a new catalytic converter. That is the only legitimate option.
>>14128770
will that actually help me with my mpgs though? theres no emissions where i live so that not an issue and id rather not spend money on it if it wont help
>>14128624
>What should I do /o/?
You should google O2 cheater and install one on your after cat sensor. That way your ECU will be tricked into thinking the cat is still there and wont dump fuel to compensate.
>>14128805
>will that actually help me with my mpgs though?
I don't know. Test the O2 sensor and see if it is good. If it isn't, replace it. Either way, you need a new catalytic converter. You living in a state where there is no inspection doesn't matter.
>>14128730
The second bank of o2 sensors are only there to make sure you have a catalytic converter. The engine uses the first o2 sensors for adjustments. If you don't want cats and second o2 sensors you can tune the computer to forget about them.
>>14128730
>
As to why your ecu would dump mad fuel in response to having to cat, I'm as lost as you are.
Limp home mode is closed circuit which dumps fuel to try guarantee the engine doesn't get raped by detonation.
Many car's ECU will do this if you remove the cat.
>>14128881
why do i need a new one
>>14128935
ooh interdasting, if i just remove the downstream o2 sensor will it stop doing that or do i have to buy one of those simulator things?
>>14128624
Is this guy gonna be alright ?
>>14129222
Because that's what your car is designed to have. Why do you want to pollute for no other reason than you are poor? If that's the case, sell this car and go buy another one that isn't broken.
Poor people, goddamn.
>>14129222
Because your car uses the catalytic converter and those O2 sensors as a gauge to see how it should adjust its fuel map.
Without that data, it has no idea how bad its farts smell and will do nothing to correct it. It's not carbureted, it can't run right without this info.
If it's dumping fuel into the pipe, chances are your sensors are completely fucked as well.
Removal of the cat on modern cars doesn't really help performance either, we long ago figured out how to make one that doesn't block airflow. Also, you do not have a racecar. You need a cat.
Get a cat and new sensors. Enjoy fuel economy.
>>14129373
don't do this
>>14129341
T H E D O W N S T R E A M O X Y G E N S E N S O R O N L Y C H E C K S C A T A L Y T I C C O N V E R T E R E F F I C I E N C Y
>>14129379
>catalytic converter manufacturer shill
>EPA shill
Cucked [ ]
Mega Cucked [ ]
Ultra Cucked [ ]
Cuckleberry Finn [X]
>>14129239
You're going to need to get your ECU to think everything is cool and operate normally. You can do this one of two ways
>Reprogram the ECU with a tuner and be done
or
>Get a signal to your ECU that it accepts as being cool
If you choose the second option you can do it one of two ways
>Install a new catalytic converter and be done
or
>Nigger rig the sensor
If you choose the later you can do it two ways
>Completely replace it with a resistor or potentiometer that sends the computer the value it expects for your particular car
or
>Put in a spacer so less CO2 gets to the sensor
>>14129341
As a fellow poor person. Most cars have a default fuel map. If you unplug the 02 sensors it'll run off the default map.
>>14129412
removing the upstream sensor can cause the engine to lean out because it has no fuckin clue how to adjust AFR in abnormal conditions
removing the downstream sensor causes a CEL which most inspection/emission places are not a fan of
Spacing the downstream sensor or installing a resistor that emulates proper behavior is the proper solution
>>14129373
What am I looking at
>>14129445
Something for idiots like>>14129391
>>14129394
what is and how do you put in a "spacer"
link would be nice
>>14128624
OP is a Troll
He made the same thread a few days ago, where he was told the exact same fix as in this thread
>>14129705
Get a new catalytic converter?
>>14129532
That's what >>14129373 is. It's cheap and easy but no guarantee it'll work right.
>>14129705
op here
not a troll just poor and not sure what to do tbqh
Anyway i just bought an upstream o2 sensor, CEL is still on and im gonna test it see if mpgs improve, hopefully they do cause that shit cost 60 bucks
Also i checked the spark plugs and theyre not carbonized or anything, theyre fine
>>14130816
You're a fucking moron. Sell the car and get one that isn't broken. You were very well advised what to do. Check O2 sensors and buy a new catalytic converter.
>>14128624
>bought a 1999 accord without a catalytic converter
You are now a federal criminal, faggot.
>>14130866
>>14130892
shits expensive, yo
Can the downstream o2 sensor really fuck up MPGs that much though? like 10mpgs on a 4cyl
>>14130946
Yes, not having a catalytic converter can do that. Sell the car and buy one with a functioning emissions system. Stop being a childish asshole.
I run my car perfectly with no catalytic converter... Shit, ive run it open header for a couple months before... It's all about that ecu code most likely. There's ways to trick the ECU into thinking you have a cat. How else do you think all these Honda guys straight pipe their cars?
long story short, dont sell that shit. fix it. do your research
>>14129428
>>14129412
This and this
>>14130816
>thread advises OP to trick downstream oxygen
>OP: just bought an upstream o2 sensor
Got baited hard.
