P0300 Code...FML
#24
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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.
#25
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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.
#26
Registered User
iTrader: (1)
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.
Last edited by djamps; 03-24-2011 at 12:04 PM.
#29
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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.
#30
Registered User
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...
Last edited by djamps; 03-24-2011 at 01:57 PM.
#31
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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?
I think the post cat ones might affect gas mileage minimally but who drives Zs for gas mileage anyway?
Last edited by rkemp1; 03-24-2011 at 03:03 PM.
#32
Registered User
iTrader: (1)
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?
I think the post cat ones might affect gas mileage minimally but who drives Zs for gas mileage anyway?
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.
Last edited by djamps; 03-25-2011 at 05:02 AM.
#35
Registered User
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.
#36
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
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.
#37
Registered User
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.
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.
#38
Registered User
iTrader: (1)
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.
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.
Last edited by djamps; 03-26-2011 at 03:58 AM.
#40
Registered User
Thread Starter
iTrader: (2)
Join Date: Jul 2007
Location: Rockville
Posts: 1,634
Likes: 0
Received 0 Likes
on
0 Posts
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)