Cat/02 CEL Q?

TheNailman

Warcock
Ok, first and formost, im getting a P0420. (cat low efficiency. .. )

im running a catted invidia V3 downpipe, and have been for almost 2 years now. never a problem with it.

my car currently has 60,000 miles on it. for the past 2000mi or so, i get that CEL. and keep deleting it. sometimes it comes back in 10 mi, sometimes in 300mi. . . .

currently i am running stock tune, with intake, inlet, uppipe, EL headers, the above mentioned downpipe, and catback.

i dont believe the cat is broken up or clogged so i dont really think the cat is the issue. but if it were an 02 sensor going screwy, wouldnt i get an 02 sensor code? ive asked around and gotten a bunch of shrugged shoulders...
default_smile.png


any ideas?

 
you need to get the o2 cel fix which take the rear o2 sensor and pulls it out of the dp sort of it ;ooks like the old anti-foul thing they had for sparkplugs.you screw it into the dp and then screw your o2 into it they are all over ebay.i had this issue with the white wrx wagon and that's what fixed it

 
The front o2 reads for the engine and computer to gets things nice and powerful for the engine. The fuel input is adjusted by what the front o2 is feeding back to the computer.

The rear o2 just monitors for emissions, to make sure the cat is doing its thing. People sometimes fool the rear o2 to get the desired readings to prevent CEL, like Gabe was saying to get the rear o2 out of the stream, and sometimes people use resistors, or both. Sometimes people just have the p0420 disabled. The rear o2 isn't really needed for keeping the engine running correctly, smoothly, efficiently. Its just added because someone in Congress decided its a lovely tree hugger thing to do.

If you are concerned about your emissions change the rear 02. If that doesn't work, put the stock cat back on, or vise-versa. I've never had a case of stock WRX with a P0420 that did NOT need a cat. My guess in the guessing game is you need a cat. Rear o2s rarely fail without another rear o2 code like a circuit out of range or heater circuit low code.

You can test it easy enough. Put the stock DP back on, clear code and see what happens. If code come back slap a rear o2 on it, clear, and see what happens.

 
Have someone with rom raider disable the code off for you. Then you'll never see it again!
this sounds good to me.

Also, what the mess are you doing running all those mods without a tune? That is like owning a dishwasher putting it in your house and never hooking the water lines up to it. Or something like that.
default_additional_gavel.gif


 
ok ok. . . .guess inski makes the best point. . . .

and as for you diablo. ... i have a pile of parts going on in the next month or so. and they will fuq up any tune i have in the meantime. i'll get one once the installs are complete.
default_additional_gavel.gif


 
The front o2 reads for the engine and computer to gets things nice and powerful for the engine. The fuel input is adjusted by what the front o2 is feeding back to the computer.
The rear o2 just monitors for emissions, to make sure the cat is doing its thing. People sometimes fool the rear o2 to get the desired readings to prevent CEL, like Gabe was saying to get the rear o2 out of the stream, and sometimes people use resistors, or both. Sometimes people just have the p0420 disabled. The rear o2 isn't really needed for keeping the engine running correctly, smoothly, efficiently. Its just added because someone in Congress decided its a lovely tree hugger thing to do.

If you are concerned about your emissions change the rear 02. If that doesn't work, put the stock cat back on, or vise-versa. I've never had a case of stock WRX with a P0420 that did NOT need a cat. My guess in the guessing game is you need a cat. Rear o2s rarely fail without another rear o2 code like a circuit out of range or heater circuit low code.

You can test it easy enough. Put the stock DP back on, clear code and see what happens. If code come back slap a rear o2 on it, clear, and see what happens.
Dave Matthews with another killer post.
default_smile.png


 
my rear o2 has been disabled since like day 4 of owning my car. i did mine whilst reflashing with an xpt map though

 
Borrow Mark's rear O2, he's not using it.
default_smile.png


I know you have serious concerns about this due to the MA inspections. If its like Cumberland County or NH we also have to make sure your OBD monitors have run, or can run if you have AP. I have read on Nabisco a kid in CO needed to remove his AP because they check the OBD monitors in CO and the AP wasn't letting them run. I'm not sure if this is a wide spread AP issue or not. I'm not wicked familier with it. I'll check on someone's car soon.

Its an easy enough check, just plug in any generic OBD compliant scanner and scroll down to see if any monitors are incomplete. If not you're good to go for inspection. You have a razor's edge to walk but its do-able.

 
Back
Top