I am getting a upstream o2 sensor and a system to lean code and even though i swapped out the o2 sensor the codes remain(disconnected battery too reset computer as well). I also checked the wiring for cuts but did not see anything wrong.


Thoughts, maybe a bad map or another sensor maybe fcd? Car runs lean into boost 14.7(does not move till 6psi) and at wot 10, its a stock hahn map on the portfueler, even added 10% to map to see if that would change it and all it did was make wot run richer. Fuel pressure is fine at 49psi and does go up when in boost.

What should the voltage be at the map/o2 sensor?

any help would be awesome thanks in advance.

kevin

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13psi on a built bottom end with a stock now mtx, check mate.

Possible exhaust leak prior to O2 sensor - sucking in a bit of air will throw the sensor more towards lean conditions. Check your exhaust mani gasket or turbo flange?

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2012 2500HD LML

there is a very small leak between turbo and mani i really don't think that will do it but i will order a new gasket for it see if that makes a differnce.

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13psi on a built bottom end with a stock now mtx, check mate.

Regardless of the CEL you are getting, if you are on the stock Hahn PF map, you should not be running an AFR of 14.7, or anywhere near that lean, until you hit 6psi.

The Hahn PF kicks in as soon as it senses boost, and if you are on the stock map, you should be in the 10's as soon as you see any boost.

Is the signal line (vac line) to the PF module ok? Also, are you running a boost only vac line to the FPR? I have heard mixed things about this, but Hahn says to use a boost only line.

Dave may be on to something with the exhaust leak sucking in air and causing the 02 to throw a lean signal. If the 02 was actually bad, it is more likely you would run rich, not lean, as the ECU dumps fuel as a failsafe.

1999 Eclipse GS
Built motor
Hahn 16G Turbo w/ FMIC
Hahn Stage 5 Portfueler (270's & 500's)
Zeitronix Zt-2 wideband w/ 3.5bar MAP
3" SS Turbo Back
CM Stage 4 Clutch and Fidanza Flywheel
Baer Big Brake Kit

good info, i will make sure the line to the portfueler is no kinked, it does have its on vac line. And i will replace my gaskets to seal it up nicely.

Thanks for the info guys, i will report back after i get the new gaskets on.

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13psi on a built bottom end with a stock now mtx, check mate.