Code P0430 - Aftermarket Exhaust
 

Hey guys, first time posting here. I just had my "Service Engine Soon" light come on after buying my 2014 370z 3 months ago. There are about 15k miles on the car, and the previous owner had a custom exhaust installed, as well as dual air intakes(as far as I can tell; Nissan dealership didn't include details on what modifications he made).

I took the car to a nearby AutoZone and they told me that it was a Code P0430 and that I should just use premium gas with an octane boost(I already use premium) and to check the air intakes for any problems.

The sound coming from the air intakes is much more audible now, and it seems to be noisier at 4k rpms(I haven't gone much higher since the engine light turned on, don't want to screw anything up). Is the AutoZone employee's advice correct or could it be a lot worse, like having to replace O2 sensors/the entire cat? Thanks for any help.

One (or more) of the O2 sensors may be bad.

You may have an air leak.

Google is your friend.

Octane booster will do nothing for the code given.

If you have test pipes installed, it would definitely set off a p0430. Take a pic of your exhaust if you can.

You have to find out exactly whats in there. If it was custom exhaust, I wouldn't imagine being very poorly made. P0430 its catalyst efficiency code which is pretty much telling you that your cat is not doing its job. Sensor itsself should be fine. Usually if it was going bad, it would throw different code. You either missing cats, have exhaust leak or have aftermarket test pipes/hfc which could throw occasional CELs.

Here are a few pictures of the exhaust. I tried to get as low as possible

I took a video as well: https://youtu.be/aTGBZwmLkMk

I'm not sure if I got the catalytic converter in the video or not, sorry.

I'm not 100% positive, but at 22 seconds in it looks like those aren't the OEM cats. My best guess is that you have three breather mods (intake/hfc/exhaust) and need a ecutek/uprev tune.

Looks like you have resonated test pipes to me but I could be wrong. An extended o2 bung might solve the problem.

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Going to a muffler shop(that I trust) tomorrow morning to get it checked out. In the meantime, any idea what this is?

You can see it at 0:04 and 0:33 in the video up above as well.

From the pics it looks like you have resonators I do not see any catalytic converters there. How did you past inspection or smog? The code P0430 should be a faulty camshaft position sensor. I had this same code on my 350Z and I had to replace the camshaft position sensor with a Denso brand sensor. Did the last owner install aftermarket camshafts? I have hear of faulty O2 sensors on these cars with or without a code being thrown. The only fuel you should be using in your 370Z is 91 octane gasoline or higher. Be careful using octane booster because curtain brands can damage catalytic converters and 02 sensors. Read the instructions before using any octane booster and make sure it says it is safe for catalytic converters and O2 sensors. A lot of brands of octane booster are for racing or off road use only.

P0430 is catalyst efficiency below threshold bank 2. You are confusing with p0340 which is related to camshaft position sensor.

Took it to a nearby exhaust shop and they told me there aren't any catalytic converters. The Nissan dealership did tests before selling the car to us(certified pre-owned) and everything came back good in terms of their emissions testing. Not sure what to do now, since it will likely not pass an annual emissions test in my county. Going to have to call up the dealership and see if they can fix things based on the warranties it came with.

Now is your chance to get test pipes with high flow catalytic converters. Aftermarket catalytic converters flow a lot better and your 370Z will make more power running high flow aftermarket catalytic converters vs. the stock Nissan catalytic converters. The stock Nissan catalytic converters are a restriction in exhaust flow on the 370Z. This code P0340 you got on your 370Z does differ from the code P0340 I got on my 350Z. Most of the time you will get the P0340 code on your 370Z if you either don't have catalytic converters or your catalytic converters failed and need to be replaced.

You might want to look into your emission requirements first, I'm from Ontario we only need emission testing after the car is 7 years old so might not be an immediate problem. And as suggested above a high flow cat is a good option, but as for the code you could probably get o2 extenders for the bungs and stuff some steel wool in them should solve the code. There is a few threads with regards to test pipes, you could get more information from members on those.

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The car should be returned to stock cats by the dealership as I'm sure it's a violation of some sort of federal law to sell a non emissions compliant vehicle. That's boring, so what you should do is have the car tuned. Either ecutek or uprev will take care of it, and give you a better running car with a lot safer tune for those modifications. There are a couple of reputable tuners in TX, I think jtran is in Houston and comes highly recommended on this forum. Or you can have the car remote tuned by specially z, Sebastian did my car and it's turned out great. Ecutek also gets you some cool features like launch control!