seafoam will just make your o2 condition even worse.... swap your o2 out maybe. also yes i meant the rear tires psi pumped to max will reduce the outbit certain percentage.

 

bad cats. replaced by infiniti under federal emissions warranty. passed with flying colors.

infiniti has no dyno, fyi. a legit smog shop has diagnose the bad cats and you still have to do convincing for infiniti to replace them.

 

It would help if you post your actuall smog numbers. If you are only off by a little get some "Gauranteed to Pass" Fuel additive at any auto store. NOX is usually cause by a lean condition= Running hot. Try to richin it up and retard the timming some if possible which I don't think is since its computer controlled. Intake leaks causing lean conditions and faulty 02 sensors showing false rich will also cause lean runs and high nox. Cats don't usually go bad unless they are real old or have physical damage. Good luck in getting everything fixed.. I'm suprised you don't have a CEL as most cases I stated would cause one.

 

The numbers are in the first post. Read the thread.

 

Damn, sorry for trying to help out.. it was late and the numbers aren't exactly below each category. Was wondering why the hell there were so many... AHahah, anyway glad you got everything worked out. Kinda suprising cats had to be replaced. I hope its not going to be the usual for our cars...

 

No prob.

It shouldn't be a problem for almost all G35s. Mine is an isolated case and I've had a bunch of crap done to my car over the years. I talked to one of the smog techs and he's said that all the 03 g35s have been passing easily.

 

Thats a relief.. I was starting to wonder if the disapearing oil issue may have been ending up in Cats and causing failure. But I think that only happened in the later years anyway. How many miles are the cats covered for anyhu?

 

I did have an oil burning problem for a bit using Motul 8100 5w40. Using Mobile 0w40 and Rotella 5w40 now. Don't seem to have the problem anymore.

 

The only thing that affects NO is the EGR system and ignition advance [timing].
Of course with a previous turbo stressed engine rings and valves, and stem seals could be worn.

 

This car doesn't have an EGR. Just a PCV valve and evap canister.

 

Sure it has EGR, just not in the old fashioned valve pipe system of the past. The VVT and cam lobe shape do the Exhaust Gas Recirculation via over lap at light load and cruise.

 

if you change the cams out does that eliminate the EGR?

 

hey guys...searched and found this thread...my car also didnt pass because of the same reason as G35pm. my reading is in the 900s. the smog guy was talking about the car running hot..what could it be? the only parts i have on the car are k&n filter, ground wires and stillen cat back...please pm me if you guys get a chance..thanks

 

Might be your cats like G35pm, I was able to pass fine with similar mods. You might want to try doing a tune up and make sure your cats are heated up before you preform the test.

About your car running hot, its prob an issue with the cooling system, can't tell you what it is but you have to diagnose the problem one part at a time.

 

took my car in to infiniti and they diagnosed that the Cats are bad ! Dont have to pay a penny ! Everything is covered under the 8 year/80k mile warranty for cats in california! woooo !