P0300 & P0174 but drives normal
 

First of all, I apologize that the 300 issues have been all over this forum many times but I just wanted you guys to hear my issue. Im new to Nissan and having a car like this. So please be nice :)

My 09 370z 6 speed, manual tranny, sports package with Test Pipes
-purchased it a few months ago, drove from Arizona to Texas with no issues and no service Engine soon light(SES).

- After a few days driving commuting to work, SES came on solid but the car didn't hesitate or anything. Drove normal. Code pulled P0300 & P0174.

- So i removed the crappy spectre intakes and installed the K&N typhoon intake, Cleaned MAF(with MAF cleaner), Cleaned Throttlebody, installed new NGK spark plugs and light still comes on solid. Same two codes

-Its been like this for a month or so, SES still on but car drives normal, no hesitation, I can pull all the way to redline with no problem but i noticed the SES starts flashing ONLY between 2500RPM to 3000RPM but still dont feel any problem and goes back to solid SES when below or above those range.

--I check all the vacuum hoses already
--New spark plugs, i didnt gap it, just installed

So is the flashing telling me a misfire on a coilpack ?
can it be the Test Pipes? or maybe a leak ?
should i test the coilpack ?
Low oil ? idk just giving ideas

If theres not much i can do, does anyone know any shops around DFW who knows how to work on this car.
THANKS

PS please let me know if you guys need additional information on my car, I would like to get this issue fixed asap :tup:

Test pipes would be my thinking based on all the other diagnostics you've done. I assume you cleared the codes after cleaning MAF and TBs and they still came back? I know that's a stupid question - you said you were new, but sound like you know what you're doing :confused: :icon17:

Yes, Ive cleared the code many times and also did the ECU reset procedure. but SES comes right back on. The only reason i know to do all this is from reading previous forums. Just learning as im going :)

How would i know if the test pipes the issue? would i need to install the cats back on ? or check leaks? and how ?

My guess is that you have a leak in the intake/exhaust system. Or a bad O2 sensor. See what the O2 sensors are reading and that should help you narrow down where the problem is.

It may help to read the system description and other info in the FSM. Plus there is usually a detailed explanation of what the different DTCs mean. Great resource for the DIYer.

P0174 is Bank 2 Too Lean, right? And the P0300 is the random misfire. Maybe a bad O2 sensor? Switch the sensors and see if the code switches with it?

Do I check the voltage of the 02 sensor to determine a bad sensor ? and Ill try to switch the 2 sensors and see if the code changes. ill also check the exhaust pipes for any leaks.

Does a test pipe usually throw an SES light ?

Yes. You'll probably want to look at the long- and short-term trim values, too. I'm sure others can suggest more params to look at.

If what you are using to read/clear DTCs will read the O2 sensors, use that. If it won't, you can find OBD/CAN monitors for $20 to what-ever-you-want-to-spend. If you're going to do you own maint/repair, it's an invaluable tool.

Sorry, been a bit busy. but i finally got the readings and here is what i found.

Bank 1 sensor 1 -- no reading
Bank 1 sensor 2 -- Reading(working)

Bank 2 sensor 1 -- no reading(this is the one thats failing and showing error)
Bank 2 sensor 2 --reading(working)
I'm not sure which sensor is located where so I can replace or at least inspect them. Can someone help me guide which sensor is on headers and cats or exhaust. Thanks

here is bank 2 sensor 1- no reading
http://www.the370z.com/members/steal...8-img-3363.jpg

and here is bank 2 sensor 2 - reading
http://www.the370z.com/members/steal...7-img-3362.jpg

and here is the fuel trims
http://www.the370z.com/members/steal...9-img-3364.jpg

http://www.the370z.com/members/steal...0-img-3365.jpg

What was the outcome for this issue?

I am having the EXACT issue and it's driving me crazy. PLEASE share the outcome.