Weird occurence with CEL

NYBladeZ

I recently installed the Meisterschaft full catback paired with my fast intentions long tube headers. Prior to, I had an uprev tune done by performance motorsport while I was running straight 2.5" tubing to the stock muffler. Upon installing my Meister, shortly thereafter the CEL went on. Using my buddies OBII reader (a cool $100 tool btw) we pulled up the code P0158. After a bit of researching it looked like a bank 2 sensor 2 error, I was running rich and it was causing the secondary 02 sensor, not the afr sensor to go off. I figured I was going to burn out the sensor and later on I'd buy a new 02 sensor and install it when I got a retune (if and when the HPS intake tubes arrive).

However, last night after filling up the gas tank I jump in and the CEL is still on. I ran home grabbed a few things, jumped back in and the CEL is OFF! I drove for about 30 miles and it remained off?!?! I used the OBII reader, it initially gave the stored trouble code, no additional codes, I cleared all codes and still haven't had the light come on. I can run another OBII reading after 200 miles.

Does anyone have a hypothesis as to why the CEL would go off? I'm not complaining, but I figured the tune hasn't changed, even after I did the pedal trick the light still remained on and it seems really weird that all of a sudden it would go off.

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2009 Carbon Fiber/Red 370z aka Trish: Sports Package, Meisterschaft full catback, Fast Intentions Longtube Headers, Injen Long Tube Intakes, UpRev Tune: Sold
2008 Lotus Exige S Club Racer aka Bella, always leaves me smiling

HKYStormFront

CEL's come on when the car is detecting a fault, usually emissions related. the light did not come on because the o2 sensor wasn't faulting at the time, though it will store the code in the computer so you can't pass emissions inspections. it will probably happen again though the next time the o2 sensor can't adjust enough to the a/f ratio you have going on in the pipes. a tune will help with this, but also, you can have them turn specific codes off in the computer so it won't come on regardless while tuning usually, that may be your best bet

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Patrick // 06 Frontier 6spd Nismosis // Mods: Uprev Tuned @ Z1 Motorsports: 257whp & 292 ft lbs
09 Pontiac G8 GXP // M6 // Sunroof // Tint... For now

NYBladeZ

I already have a tune, that tune is to rich up top for the exhaust setup. With the new y pipe design I'm allowing for more backpressure thus running rich. I don't think the sensor is faulty though if you run rich over time you'll burn them out, a fact I learned the hard way. Is it possible that the ecu corrected itself, leaning out the afr causing the light to go off? I guess there is no way to confirm the code is gone until I drive the neccessary 200 miles to see if the CEL comes on and scan it again with the OBII.

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2009 Carbon Fiber/Red 370z aka Trish: Sports Package, Meisterschaft full catback, Fast Intentions Longtube Headers, Injen Long Tube Intakes, UpRev Tune: Sold
2008 Lotus Exige S Club Racer aka Bella, always leaves me smiling

HKYStormFront

i don't think it would, it's only got a certain range that it's designed to work within, but i'm not sure

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Patrick // 06 Frontier 6spd Nismosis // Mods: Uprev Tuned @ Z1 Motorsports: 257whp & 292 ft lbs
09 Pontiac G8 GXP // M6 // Sunroof // Tint... For now

Jordo!

I know you can adjust the thresholds for the CEL on certain parameters. Might be you need to have the tune adjusted a wee bit and are occasionally tripping it even with retuned thresholds.

That particular CEL can also just be turned off permanently.

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Enjoy it. Destroy it.

christian370z

Well, the ECU will display the CEL for a period of time after the event that originally caused it, even if that event only happened at one point. Eventually, the CEL will turn off if the fault is not seen for a certain period of time.

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-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob