HELP having issues on bank 2 lean

GuiLLoZ · 06-04-2018, 12:07 PM

had a p300 missfire then a 302 which is cilinder 2 i replaced de coil and problem solved (not quite) currently i went to retune my car with ecutek. the tuner said the bank 2 was leaner he was giving the same % of gas and the bank 2 didn't responded stayed on 13.5 and the bank 1 was on 11.8.

He then loaded a map for turbo with the speed density to see if the mafs where the problem. Nope still bank 2 lean, then he said check your o2 sensors they are reading different voltage even 1 volt difference which he pulled other 370z logs and the o2 where slightly parallel to one another. i am planning on changing again my o2 sensors. He tuned individually bank 2 making it richer to maybe even the odds until i change my o2 sensors and try again.

My question is: is there something else causing this? voltage and the bank 2 be leanner other than the o2 sensor, don't want to think it is an injector problem in cruise he performs great, even thou my mpg are 13.8 which before was 15.4. Maybe a vacuum leak? but for now i am

and if this keeps up maybe sell the car.

ByThaBay · 06-06-2018, 04:37 AM

Quote:

Originally Posted by GuiLLoZ

had a p300 missfire then a 302 which is cilinder 2 i replaced de coil and problem solved (not quite) currently i went to retune my car with ecutek. the tuner said the bank 2 was leaner he was giving the same % of gas and the bank 2 didn't responded stayed on 13.5 and the bank 1 was on 11.8.

He then loaded a map for turbo with the speed density to see if the mafs where the problem. Nope still bank 2 lean, then he said check your o2 sensors they are reading different voltage even 1 volt difference which he pulled other 370z logs and the o2 where slightly parallel to one another. i am planning on changing again my o2 sensors. He tuned individually bank 2 making it richer to maybe even the odds until i change my o2 sensors and try again.

My question is: is there something else causing this? voltage and the bank 2 be leanner other than the o2 sensor, don't want to think it is an injector problem in cruise he performs great, even thou my mpg are 13.8 which before was 15.4. Maybe a vacuum leak? but for now i am

and if this keeps up maybe sell the car.

Somewhat of a common issue - there is likely a hairline crack on one of your cats. I’ve seen the cracks hidden behind the cat heat shield.

GuiLLoZ · 06-06-2018, 12:30 PM

Quote:

Originally Posted by ByThaBay

Somewhat of a common issue - there is likely a hairline crack on one of your cats. I’ve seen the cracks hidden behind the cat heat shield.

i don't have cats

fryzia23 · 06-06-2018, 12:53 PM

I see you have stillen CAI. I would check all the clamps on bank 2 just to make sure you have no metered air going in. Also since your exhaust is custom, I would definitely check for leaks there as well before you start throwing parts on it.

ByThaBay · 06-06-2018, 02:37 PM

Quote:

Originally Posted by fryzia23

I see you have stillen CAI. I would check all the clamps on bank 2 just to make sure you have no metered air going in. Also since your exhaust is custom, I would definitely check for leaks there as well before you start throwing parts on it.

If he ran speed density and still had the same issue, the CAI wouldn’t matter since speed density is based off manifold pressure. I would look at exhaust manifold leaks or check the gaskets where the test pipes meet the manifolds. You could also try swapping A/F sensors. Also there may be a light misfire condition or an injector issue.

GuiLLoZ · 06-08-2018, 01:21 PM

Quote:

Originally Posted by ByThaBay

If he ran speed density and still had the same issue, the CAI wouldn’t matter since speed density is based off manifold pressure. I would look at exhaust manifold leaks or check the gaskets where the test pipes meet the manifolds. You could also try swapping A/F sensors. Also there may be a light misfire condition or an injector issue.

will do that i'll swapp sensors to see if the problem shifts to bank 1 or stays the same.

B&W_Evader · 06-11-2018, 11:30 AM

I believe there's a fused heater in one of the O2 sensors. I think it's the post Cat one. They have been known to blow and it's a cheap/easy fix if it's just the fuse.

GuiLLoZ · 06-18-2018, 11:20 AM

where is it?

shadow85 · 01-07-2020, 10:04 PM

Did you get to the bottom of this? What was the issue?

06-04-2018, 12:07 PM	#1 (permalink)
GuiLLoZ Base Member Join Date: Dec 2014 Location: Puerto Rico Posts: 81 Drives: 13 KaD M6 Rep Power: 11	HELP having issues on bank 2 lean had a p300 missfire then a 302 which is cilinder 2 i replaced de coil and problem solved (not quite) currently i went to retune my car with ecutek. the tuner said the bank 2 was leaner he was giving the same % of gas and the bank 2 didn't responded stayed on 13.5 and the bank 1 was on 11.8. He then loaded a map for turbo with the speed density to see if the mafs where the problem. Nope still bank 2 lean, then he said check your o2 sensors they are reading different voltage even 1 volt difference which he pulled other 370z logs and the o2 where slightly parallel to one another. i am planning on changing again my o2 sensors. He tuned individually bank 2 making it richer to maybe even the odds until i change my o2 sensors and try again. My question is: is there something else causing this? voltage and the bank 2 be leanner other than the o2 sensor, don't want to think it is an injector problem in cruise he performs great, even thou my mpg are 13.8 which before was 15.4. Maybe a vacuum leak? but for now i am and if this keeps up maybe sell the car. __________________ Stillen gen 3 CAI/koyorad oilcooler/custom full exhaust/ecutek/20mm spacers/megan springs

06-11-2018, 11:30 AM	#7 (permalink)
B&W_Evader Track Member Join Date: Aug 2011 Location: CA Posts: 972 Drives: slower than before Rep Power: 387	I believe there's a fused heater in one of the O2 sensors. I think it's the post Cat one. They have been known to blow and it's a cheap/easy fix if it's just the fuse. __________________ \|RIP\|6spd-sport\|OSG-LSD\|XP8\|RBF600\|Eibach Sways\|RE-71R\|FI-34Row\|Gen3-CAI\|Yaw P.S.\|

06-18-2018, 11:20 AM	#8 (permalink)
GuiLLoZ Base Member Join Date: Dec 2014 Location: Puerto Rico Posts: 81 Drives: 13 KaD M6 Rep Power: 11	where is it? __________________ Stillen gen 3 CAI/koyorad oilcooler/custom full exhaust/ecutek/20mm spacers/megan springs

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06-06-2018, 12:53 PM	#4 (permalink)
fryzia23 Enthusiast Member Join Date: Dec 2010 Location: new jersey Posts: 452 Drives: 2011 MB 370Z NISMO Rep Power: 1246	I see you have stillen CAI. I would check all the clamps on bank 2 just to make sure you have no metered air going in. Also since your exhaust is custom, I would definitely check for leaks there as well before you start throwing parts on it.

01-07-2020, 10:04 PM	#9 (permalink)
shadow85 Track Member Join Date: Jul 2015 Location: South Australia, Austra Posts: 918 Drives: 15' 370Z A/T AMM TT Rep Power: 25	Did you get to the bottom of this? What was the issue?