On my 07, I have test pipes. Other Mods are in my sig. I am now running STOCK AIRBOXES. they seem to fluctuate the RPMs less than the AEM intakes.

I had been getting CELs for a long time, but it seemed to be affecting my performance. The car would sputter on hard accelerations, and it would bog up under heavy load. The exhaust note changes to a higher pitched, more obnoxious sound.

So i decided to check the codes.
The codes are P0420 and P0430

I had it checked out, and it was determined that the passenger side O2 sensor was installed wrong and was leaking air. That was reinstalled.
It drove fine for about 80 miles after clearing the two codes. However, after these 80 miles, the same codes came up, and the same problems as well.
Also, there seems to be no leaks between the manifold and test pipe connection.

I cant figure out whats going on... Any suggestions? Also, what is the OBD code that you all get with your test pipes?


Tanks
-SB

 

I need some fast responses please guys. I need to find a solution to this as fast as possible.

Also, i forgot to mention, MPG decreases with this CEL.

 

Those are the codes you get with test pipes.

put your cats back on and i bet your codes go away.

i dont think that even the defoulers will help those codes with the late model Z's.

might need an electrical O2 sensor trick

 

They are the same codes as what everyone else gets?

Well i dont understand how its affecting my cars performance then...

 

PP0420 TW (Two-Way) Catalyst System, Bank 1
PP0430 TW Catalyst System, Bank 2

These codes suggest you don't have any kind of leak or problems with the sensors.

The problem is the sensors are correctly seeing a lack of catalytic conversion of the exhaust gasses.

 

Right... thats what i though.
but why does the exhaust notechange with the CEL and why does my MPG decrease?

 

Changes in cam phase can do that.
But I cant say why it may be changing.

 

Should I take my car to a nissan dealer? Would they be pissed about warranty things?

 

Probably not.
At least it would be good to definitively know what the issue is.

 

I think i will bring it there on saturday and find out.
And thanks for your help. Youve been a big help through this issue lol. All the way from the first thread.

 

had the same problem with my '06 with HFC, Took it into a Nissan dealer and they said I should take the HFC off ASAP because the cats where breaking apart? I looked at them, they were fine. Nissan is a waste of time. I still have the codes though. I called and talked to a ton of techs at various places, all said the same thing which was that the '05.5 and up year Z's O2 sensors are very sensitive. Good luck and I hope this at least saves you a headache at the dealers

 

didn't have the issue with the hfc's but did w/ the test pipes

the codes you are getting are infact because of the test pipes. i believe the spacers from what i've heard don't make a difference on the 07's unfortunately. the only way i believe would be 02 simulators to elimate this condition. i have not experience the exhaust note change that you have been experience however i hope you are not talking about the sputtering issue between 2k and 3k rpms that a lot of hr's are experiencing. check out the vq35hr forum for the sputtering during warm up. this issue has been effecting me for awhile and my wife sondra's car as well. however since the aam reflash on sunday i have not experienced where sondra has still been experiencing it. keep in mind the test pipes eminate a different sound then HFC's. best of luck with your quest on elmiinating your cat codes and if you do elinate them w/o the 02 sims let me know.