djamps

iTrader: (1)

^^ this...exactly what happened when I lost a coil pack (twice)

03threefiftyz

iTrader: (25)

The fact that he just installed an intake screams Maf issue, though.

djamps

iTrader: (1)

Yea but that would affect both banks not just one as he described.

Simple test... let it idle and unplug/replug each coil pack. If one of them doesn't change how the car runs, there's the bad one.

rkemp1

iTrader: (2)

Turned out to be a pre-cat 02 sensor on the driver side. Much less worrysome than I expected last night (hydrolock fears). Guy at JE ran a diagnostic and got an additional code to what I originally had. A P2A00 Air fuel ration sensor bank 1 sensor 1. I am going to replace that and hope that does it. Thanks for all the tips and ideas guys.

rkemp1

iTrader: (2)

Man I would have loved to do it but when a dealer tries to give me 11k on a car in as good of condition as mine with so few miles I have to walk away. I even had Sondra check the numbers and the resale/trade-in value but the 07 350z sucks *** even with low miles.

djamps

iTrader: (1)

A blown coil pack will cause that bank to run way rich and hence you're going to get a o2 code as well. I hope they ruled out all the coil packs before making you buy an o2 sensor. Neither are very cheap.

rkemp1

iTrader: (2)

Hmm, I didn't know that, I will ask about that before letting them complete the install. Thanks for the tip

superchargedg

iTrader: (4)

Front o2 sensors usually dont do much as its the rear ones that do most of the work....interesting to see the outcome of this being it's a 2007 with wideband sensors.

rkemp1

iTrader: (2)

Its the other way around... for 07s at least... I am not sure about the other years. The front O2 sensors pre cat send signals to the ECU to adjust A/F and the ones post cat just check to make sure the cats are working efficiently. I have had the post cat 02 sensor lights on ever since I put the test pipes on 4 yrs ago. Been running strong until now... I am just hoping that all it is. If its coils those are much more expensive.

djamps

iTrader: (1)

Interesting, where did you hear that? I'm trying to research exactly how the ECU (my '04 at least) uses each set of sensors... ever since installing antifoulers on the lower sensors my A/F is jacked up at low load intermittently (as seen by the upper wideband sensors and confirmed by my AEM UEGO). My thoughts are that the ECU uses both -- the lower o2 sensors mainly for steady cruising and the uppers for idle and acceleration. I'm going to pull my antifoulers this weekend and see if it changes anything...

rkemp1

iTrader: (2)

its pretty universally known from what I thought. I shouldn't imply that the secondary sensors do absolutely nuthing but they def don't do much. I won't pretend to know everything about emissions but the original installer of my test pipes a few years ago told me they don't do much. Even Frank told me that when he checked my engine light with his scanner. I believe it too because my car posted about 295 to the wheels while throwing those codes with minor bolt ons. It also makes sense because the car didn't have these problems until the pre cat sensor code popped.

I think the post cat ones might affect gas mileage minimally but who drives Zs for gas mileage anyway?

djamps

iTrader: (1)

I think you're right. The post cat sensors seem to be used only for light cruising (e.g. gas mileage affecting) and the uppers used for idle and mid to WOT. I used to only get catalyst codes after long periods of cruising...so that kind of goes along with the theory.

I agree about the gas mileage thing... but when I'm averaging about 12mpg the more I can get the better LOL. I've been focusing on cleaning up my low load areas of the tune.

03threefiftyz

iTrader: (25)

I get 30mpg in my Z on the highway on the performance map .

Alberto

iTrader: (14)

Wow thats terrible. If I cruise in my car with 2 pumps, 1000cc injectors and a good tune I have avg'd as high as 24mpg. WOT duty and play time is 10mpg.

How rich are you running at cruising throttle?

djamps

iTrader: (1)

I was exagerating a bit but I'd say 12mpg worse and 16mpg best... lately my cruising A/F has been floating between 12 and 14 ever since installing non-foulers..and I've been unable to tune it out. I pulled them off today and it's back to 14.7 steady so hopefully I'll get some MPG back.

rkemp1

iTrader: (2)

Yeah I hear you on the more the better comment. Especially with gas prices going up. I would love to see 20+mpg.

This whole case with my car just got weirder. I drove it home after letting them run the diagnostic since they would have to order the part and the symptoms are completely gone! Drove it this morning and afternoon and no more hesitation or sputtering.

jeffie7

iTrader: (4)

first O2s I believe are the main source of info for the car, the 2nd set of O2s check the difference in the before/after cats fuel reading. If the readings are not far enough apart (readings not showing a big change before cat and after cat) If it doesn't show a big difference it will think the cats are shot then it will throw a flag aka code.

Regardless, anytime the MAF could be an issue, pop it out and clean it, takes very little time to do and can rule out a dirty MAF.

djamps

iTrader: (1)

I just verified by removing my lower o2 non foulers and the A/F is now spot on 14.7 and no more 'float' or 'wander' at idle and cruise. It also responds a little better at low rpms... so both wide and narrow bands are definitely used for the ECU trims, at least on a 2004.5. I'd suggest anyone with non foulers to take that **** off -- they could be seriously affecting your tune as did mine.

jeffie7

iTrader: (4)

Did you get the car tuned before or after adding the non foulers?

rkemp1

iTrader: (2)

looks like it was the primary 02 sensors. Got em replaced this morning and the car is running smoother than ever and I cruised home with a nice 23mpg.(thats high for me)