Ok, what the Fuck. check engine light stuff.

[HeavyMetal]

This is the second time this has happened. 2 years ago i replaced my o2 sensor, and less than a week later it read it was bad. I decided I didnt care. fast forward to now when i have to pass emissions. I replaced Both sensors. Check engine light went off for around 200 miles...came back on. Throwing the o2 code.

21 - Oxygen sensor or circuit. O2 sensor or wiring faulty.

I must have something messed up.

Oh and this stupid fucking thing has been plaguing me for years also:

42 Automatic shutdown relay. Check relay and circuit. Needs specialist or dealer diagnostics.

there is a relay for this, ive replaced it before (again, years ago)..but to no avail.

and no one can find a solution for it for me.

what the hell! help!

[kappy]

is the code for a upstream or downstream? Shorted wire, bad cat maybe

[HeavyMetal]

is the code for a upstream or downstream? Shorted wire, bad cat maybe

im running the code via the jeep itself, not a reader, so i dont have something that specific, all i know is that code i posted right now

guess i should snag a reader to get a better idea?

[Mike]

Havent had emissions done in YEARS but do they only fail you if the CE light is on? Its pretty easy to pull the gauges out and pull that light out so it doesnt light up.

[HeavyMetal]

Havent had emissions done in YEARS but do they only fail you if the CE light is on? Its pretty easy to pull the gauges out and pull that light out so it doesnt light up.

they plug it into a machine, the CEL itself isnt what nails you in the end.. from what i can tell/hear there is no tricking your way through it

[Ktmracer419]

Havent had emissions done in YEARS but do they only fail you if the CE light is on? Its pretty easy to pull the gauges out and pull that light out so it doesnt light up.

they plug it into a machine, the CEL itself isnt what nails you in the end.. from what i can tell/hear there is no tricking your way through it

there is no tricking through it, they do a command test for the light as well as do it through the fancy compooda

at least in rhode island you need to drive a few hundred miles to reset the monitors after you shut off the cel

[Saharicon]

Did you wheel between those 200 miles that it stayed off?

[Ruepart Hoaxley]

check the o2 sensor wiring, mine had frayed shielding underneath from friction. trace it back as far as you can and see if you can find a short

[kappy]

Ya in CT you have to drive a few hundred miles to get rid of the p1000 code if they see that you fail instantly

[ninetysix-ex-jay]

at least in rhode island you need to drive a few hundred miles to reset the monitors after you shut off the cel

Dis be troof in CT also

[clean4drxj]

check the o2 sensor wiring, mine had frayed shielding underneath from friction. trace it back as far as you can and see if you can find a short

as similar to what he stated, check the wires, makes sure all your connections are good and last possibley worst case replace the cat..

[JeepJuggalo]

sometimes something else is wrong making the o2 out of range, but triggering that code. i asume based upon the code numbers its obd1 not 2 if its obd1 and you think its runnin well pull the light bulb for it. they are going to t-pipe and dyno it, not hook it up to the computer. that is only done on obd2 cars, 96+ get plugged in and ran bout 5 min. it only takes 3 drive cycles for the computer to be totally clear and be retested about 40 miles. idleing, drive=ing accecerating.

[1cleantj]

will what year is your jeep ? if its before 2001 (96-2000)you can pass with 2 sensors not ready. You can technically pass a vehicle with codes. You will have to get/borrow a code reader that has I/M monitor ready/not ready read out. Clear the codes, start up your jeep, drive down the highway at a constant 60-65 for 10miles or so., find a nice stretch of road you can do around 35mph on constantly for around 5minutes. With the reader plugged in while you drive, keep checking the ready status of the monitors. You should be able to get everything but Evap monitor and catalyst ready. Do not shut it off., drive to emission's place and have them test it (preferably a shop that will keep it running for you while they test).

Pretty much Most Hard codes, as in codes that set off the check engine light.

a code will be in "Pending" status until a few key cycles of the same code being set. Pending codes will NOT show up on emission testers.

[Saharicon]

check the o2 sensor wiring, mine had frayed shielding underneath from friction. trace it back as far as you can and see if you can find a short

This is what I was going to say, if you didnt wheel those 200 miles it might of not jared the "short" around enough. Since it went away when you replaced both of them you might of moved the connection/wire on the 2nd one that has the short when you did both.

[Ruepart Hoaxley]

My wires are tyrapped in position underneath so it doesn't move out of a "good"position.