So.. i havent been on this site in a few months now. I got laid off from work and havent had money to spend so havent really been on here or interested in modding my car anymore.

Anyway, my car is a 2006 SC/SS. its all stock performance wise except for my AEM CAI, and ive got a full exhaust (badmab header, zzp's high flow catted down pipe, and a corsa catback). Now, ever since i put these things on my car somewhere around a year ago ive been getting a P0171 Code, which im aware is just a lean code and the car needs a tune to get rid of it, other than that, all should be good. The CEL's for that code always go away on their own after a day or so. but recently ive got a CEL on top of the P0171. and it does not go away. Ive tried clearing it and it just comes back on. btw the code is a P0420 which if u dont know off the top of ur head is the dreaded CAT CODE. I do know that there was a recall for the cat's for these cars but obviously my aftermarket cat isnt affected by that.

now, im not that farmiliar with this code as ive only seen it a few times at work and never asked much about. im looking for help guys so im wondering if this is basically a definite bad cat if its just another stupid code that pops up from not having a tune. So please help me out here guys.

thanks in advance

 

I changed out my bank 1 O2 sensor and she ran so much better. I did read out the bad sensor with a meter to be sure too.

 

r u trying to tell me that an O2 sensor is causing a P0420? wouldnt i get a seperate code for an O2 sensor?

 

aftermarket cats do not filter the exhaust up to factory specs.....it is a low efficiency code. If you are running an aftermarket cat you will probably continue to have that code come up. So you can try a defouler, or have the car tuned and the code deleted.

 

yup, thats the aftermarket cat.

 

please refrain from using profanity in thread titles in the future



Also, to add to the thread, any aftermarket downpipe, catless or catted, can throw that code. With the exception of for state inspection, leaving it on won't hurt anything. You can get it removed with a tune.

 

Well how come ive never had this code before now tho? the car still drives the same as far as i can tell.

 

the material in the converter breaks down.....and high flow converters don't have as much filtering material as a factory piece. The car will run run unless the coverter gets plugged up.......

 

sometimes the code will not be thrown right away. I ran my car catless for over a year (with a defouler) without it throwing the code. A few months after I sold the car it finally threw the code.

 

thanks alot guys. So ill look a little more into it but more than likely its nothing

 

Get some elec tape and put it on the dash over the CEL. Problem solved :p

 

This has nothing to do with the b1s1 (first sensor) o2. As others have said, this is the b1s2 o2 (second sensor) aka emissions o2.

The P171 is absolutely related to the cai skewing your trims, and the P0420 is really nothing to be concerned about unless you need to pass emissions sometime soon. I would personally be far more concerned with the P0171 than the P0420 to be honest.

 

well luckly i literally just did emissions like a few months ago, so im not to worried about it. and ive thought the same thing as far as worrying about the P0171 lean code. Everyone always says dont worry about, but i personally think that in time it will cause damage.

 

I have a SAI and my running lean problem was fixed by replacing my bank 1 sensor. That is all I was meaning. The after market cat is a different animal. I have had the P0420 code forever now and I personally don't really care about fixing right @ the moment.

 

If anyone actually saw a log of what their trims were doing (and actually understood what they were looking at) when the code gets triggered, they just might change their tone about you "not worrying about it". Fuel trims are by nature designed to fluctuate in order to enrichen and/or lean your fuel mixture while driving, but it's only effective and safe up to a certain point. It takes a HUGE swing for a relatively long period of time to trigger that DTC, so it definitely can be a big deal if ignored.

****, seeing as how you're local, if you're feeling crazy I'd be willing to run a log on your car sometime and show you exactly what I'm talking about. It aint purdy.. lol

 

If you have ZZP's high flow catted downpipe the Cat recall won't aply to you.
The Cat Recall is for the Factory cat. If you have ZZPs Catted downpipe you no longer have a factory cat, but one from ZZP. You may just need the Downstreem O2 sensor deleted when you get your tune. Thats what I had them do. I also have a ZZP High Flow cat and my downstream O2 Sensor is deleted in my tune. If you do think you have a cat problem, youll have to talk to ZZP about it.