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GrandAmC9
12-06-2008, 07:16 PM
well i got the 2.5" dp and high flow cat from zzp and a couple weeks later my ses light went on, i took it to autozone to see what code was being thrown, the guy there gave me this whole lecture about california emmissions and federal emmissions and how this was a federal cat and because my 2000 has california emmissions on it its throwing off the code and that the only way to be able to keep the cat was to get a new federalcrank sensor,federal cam sensor, o2 sensors, and replace the rings on the cam and crank to adapt to the federal emmission system that wold be on my car after all that...

so i went onto zzp's site and got this...
The downpipes we sell come with a Magnaflow high performance converter. It is OBD2 compliant but it is on the very edge of being so. The PO 420 code is set when the rear bank O2 sensor PCM thinks that the converter is not doing a good enough job. Because the stock cat is so thick and dense, it can still function when the tune is off or it gets old. The Magnaflow isnít like that. An error in tuning, running too rich, having too cold of a Tstat, too cold of plugs, or an old primary O2 sensor can all affect the engine enough to set a code when using the Magnaflow cat. This code DOES NOT affect the way the car runs, it just sets an SES light. To fix it, youíll need that code removed from the PCM, or you can run our O2 emulator(not available for ALL vehicles), or you can clear the code and try to tune the car in better to allow the cat to operate more efficiently. This is a situation in which your cars stock sensor was not designed with your performance goals in mind. Please make your purchase with the understanding that over time, an SES light could be thrown due to the reasons stated above. This is not grounds for a warranty claim, as a repair or replace of the cat/downpipe would not permanently fix the code.

my question is can i do anything to fix this, would be replacing the o2 sensors be enough to fix this problem since they are old and i havent replaced them when i rebuilt my motor or anything(or sice i got the car for that matter)???

Malaclypse
12-06-2008, 09:57 PM
Replacing any parts is a gamble on whether or not it will take care of the P0420 code. Same with a re-tune, tune up, injector flush or anything else.

The only guaranteed fix is to go back to a stock cat or delete the code/use an O2 emulator.

GrandAmC9
12-07-2008, 12:09 AM
the guy also said that deleting the code will cause my engine to constantly flood, i really dont want to have to go back to a stock cat, im probably going to get new o2 sensors and maybe try an o2 emulator, but if anyone has had this problem or has any ideas please let me know
and if anyone is running an o2 emulator hows it work? can you fool someone for emissions with it?

McFlurrey06
12-07-2008, 12:16 AM
tuned PCM from MPR, an get rid of that sensor input all together

GrandAmC9
12-07-2008, 12:22 AM
i have one from mpr (standard) do i need to specificaly get that done? and what do you mean get rid of the sensor input? get rid of the rear o2 sensor and block off the hole?

McFlurrey06
12-07-2008, 01:13 AM
you need to ask for it. It removes the computer looking for the signals so no code and all it happy, or something like that


PM Mark for detials

KhellendrosxS
12-07-2008, 07:16 AM
Yes, you can turn off any number of sensor information when tuning a PCM. Obviously some would do quite a bit of harm if they are turned off but that is not the case for the rear O2 sensor.

Its only function is to check that the catalytic converter is working. Obviously with this being a new cat its doing its job so dont even worry about the light. Get in touch with Mark and ask him about getting that code turned off in your PCM. You can leave the O2 sensor there but it really wont matter if you take it out.

AaronGTR
12-07-2008, 09:07 AM
the guy also said that deleting the code will cause my engine to constantly flood, i really dont want to have to go back to a stock cat, im probably going to get new o2 sensors and maybe try an o2 emulator, but if anyone has had this problem or has any ideas please let me know
and if anyone is running an o2 emulator hows it work? can you fool someone for emissions with it?

Is this the same guy that said you'd have to replace the cam sensor, crank sensor, blah blah blah? Don't listen to him, he's a freaking idiot and has NO idea what he's talking about. There is only one type of sensor ring and one type of sensor for those, and you can't replace them with anything different and it won't change anything. Those have absolutely nothing to do with the rear O2 sensor anyway. And deleting the rear O2 sensor codes will NOT cause your engine to flood. It has nothing to do with fuel adjustment, the front O2 sensor does that. You should go back to that store and tell that guy he's a moron.

The code is usually set from the cat not heating up fast enough so it doesn't start burning the emissions efficiently as early as the stock cat so the pcm thinks there's a problem. It's very common with high flow cats since they aren't as dense a core as the stock cat, they let more heat through. If you have a lower thermostat or colder spark plugs, you can try switching those back to stock to try and raise the combustion temps a little. More heat in the exhaust will heat the cat up faster. If that doesn't work, have someone with a tuner turn the codes off, or get an O2 simulator. I used a sim for a long time before tuners were available and they work perfectly. :thumbs:

GrandAmC9
12-07-2008, 05:25 PM
thanks guys i think im going to get an o2 simulator first to correct the proble, but will that effect what the ecm tells the computer for emissions though?, as for visual check im just going to keep the o2 sensor in the pipe and leave the wire running up into the engine bay so it looks like it is plugged in, and wuddnt removing the code for the sensor change what the ecm says to the computer for emmissions?

i guess im asking if i should delete the code or not if it works with the o2 simulator?

gagt Mechanic
12-07-2008, 06:18 PM
in my state, if you turn off cat/rear 02 monitering, you wont pass emmisions
02 sim 101, your rear 02 works off of resistance, it has a filament in it. the hotter or colder it is depending on the amount of combustable gas going past will change the voltage. so an 02 simulator is a resistor, you plug it into the same plug as the stock 02, and it takes the voltage in and changes it to the correct return voltage to the pcm that a good cat and 02 sensor would. I would choose this over removing the 02 code.

GrandAmC9
12-07-2008, 09:19 PM
thanks, i was looking online and found this
http://cgi.ebay.com/O2-OXYGEN-SENSOR-SIMULATOR-ELIMINATOR-PERFORMANCE-CHIP_W0QQitemZ110322202514QQcmdZViewItemQQptZAU_Ca r_Parts_Accessories?hash=item110322202514&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50
is this the same thing or is it actually a resistor/smaller form

stewartfn18
12-07-2008, 10:37 PM
in my state, if you turn off cat/rear 02 monitering, you wont pass emmisions
this is not true. i passed emmisions with a magnaflow cat no prob. all they do is check for codes in the pcm. if there are no codes present then there are no problems. So OP, ether get a re tune from MPR or get a o2 sim and youll be fine.