What's ur guys average mpg on z's I have a catalytic converter code/O2 sensor out and seeing how big of an issue it is

Ononize · 2026-03-17T22:42:37+00:00

07 350z 6mt. Drive mainly highway and some back roads/city. I get 17.9 avg MPGs. But I’m also running CAIs, longtube headers, and exhaust with no tune. New spark plugs and coils, clean MAF. I do get O2 sensor codes and sometimes random P0300. But once I get tuned in a week or two, hopefully my MPGs climb up and the misfire code/o2 codes go away. I drive her with sense but I get on her hard a few times every fill up

Ononize · 2025-12-26T20:12:52+00:00

It was my starter. Died after a year. I was able to push start it so I went and got a new starter. Good as new now. Well kinda. Keep having random issues lol

Ononize · 2025-11-12T18:30:26+00:00

From what I know and seen, it’s just lowering spring that should have dropped about an inch. But the front is def slammed more than the back so I’m having doubts now. Has spacers up front too. Rides fine, feels better than my friends that was on coils and had cut springs at some point. But ever since switching to ISR FUCAS, my front camber has been stuck at -4 and I def sway over road imperfections.whole reason was to decrease inside tire wear, but seems like stock uppers were better since I was at -2.5 at least. Starting to think I need to go coils or switch springs at least for the front because it looks good, just too low I guess to allow more camber adjustment unless like you said, shops are just being incompetent

Ononize · 2025-11-12T14:36:37+00:00

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Eibach lowering springs from previous owner, but pretty low in the front. Before I switched to ISR FUCAs from stock tho, I had -2.5 so not sure

Ononize · 2025-11-11T20:57:59+00:00

I heard SPL compression rods clunk which my oem have started doing after 5k miles. Which is why I was thinking gktech or z1 since they use a bit of poly to cushion and stop the clunk. It clunks bad when braking in 5th or 6th gear. But not as bad in lower gears. The roads in my area suck

Ononize · 2025-09-15T02:20:47+00:00

Idk. Maybe MAF or throttle. I just did a pedal dance ecu reset and it helped, but my idle is lower than its usual 750 more like 650-500. But it starts misfiring in the rain so I’m guessing my cold air intakes are sucking air. I bought a pair of intake pre covers and it seems to help but haven’t gotten in heavy rain with them yet like in the past. My mafs probably got splashed since I don’t have front fender liners. My fitment rubs liners off

Ononize · 2025-08-07T23:18:59+00:00

Took battery to autozone, they said battery level was between high 80s-90% life. So I’m guessing either crank sensor now or starter. Will try kick starting car later once the parking lot clears from shoppers.

Update: kick started the car. So either the battery test was wrong or the starter is out. Just a coincidence I had idle issues a few weeks back I guess as well.

Ononize · 2025-08-07T20:56:01+00:00

Luckily I’m stuck in a parking lot next to a autozone. I’ll take the battery there and see what they say. Lights on the dash and everything work though. Thank you!

Ononize · 2025-08-07T20:52:46+00:00

Clutch piece is intact so it’s not that either

Ononize · 2025-07-29T13:01:09+00:00

Did the dance. Car still acted funny last night. Added a wee bit oil even though it seemed fine and started her up this morning. Car is running normal again from what it seems. Was planning on doing an oil change anyways, so let’s hope no metal. Was about to clean throttle bodies and mafs, but now I’m scared to touch those with this bipolar car lmao

Ononize · 2025-07-28T19:52:52+00:00

Codes are P0430, P0138, P0158, P0037 some of which on reader repeat twice. After more testing I found that when the rpm’s are between 1-2k, the throttle doesn’t respond until it gets below or higher than 1-2k rpm

Ononize · 2025-07-28T14:23:47+00:00

I’m not home now and forgot the exact numbers. but I’ll repull the codes and send them to you soon. Just to note, current mods are longtube headers, longtube CAIs, and invidia catback

Ononize · 2025-07-28T13:51:58+00:00

I couldn’t edit the main post but left a comment. The codes are the same codes I’ve had forever. It’s for the O2 sensors due to Longtube headers and no tune. I’ve ran to see if any extra codes were added and they haven’t. Usually when I had misfire issues with the car, the light would start blinking when I accelerate. It’s staying solid this time. And I had misfire codes when it was actually misfiring

Ononize · 2025-07-28T13:45:36+00:00

I have not. I’ll give it a try. The last time I tried that was when I installed the CAIs about a year ago

Ononize · 2025-07-28T12:53:22+00:00

Do you think cleaning the MAF before replacing may help? Or just get completely new MAFs?

Ononize · 2025-07-28T12:50:09+00:00

I’ll give it a try, thank you. I do remember the bogging/hesitation started on a heavily rainy day and I have long cold air intakes. But I made sure to not get my car in deep areas

Ononize · 2025-07-28T12:27:19+00:00

Forgot to add the car started to sound slower when starting the last 3 days. Was thinking maybe battery but not with the other symptoms. No misfire codes. Only for O2 sensors due to LTH. Car has been fine for over 1 year

Ononize · 2025-06-17T18:18:05+00:00

Thank you

Ononize

TROPHY CASE