02 Sensor stop reading after 20-30min drive time...
09-20-2014, 11:18 AM
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02 Sensor stop reading after 20-30min drive time... Ok, I've been trying to track this problem down. On the way home from LSFest my car all of a sudden developed a buck at steady cruising speed. Not a constant buck, but all of a sudden, felt like a left off the throttle real fast and blipped the throttle quick.
So I got home and logged the car. WB reading 14.3-15.1 when steady driving, 02 sensors swing between 95mv-873mv. STFT are right around +/-2% when I am driving.
Now here's the weird part... If I drive the car for more than 20 mins they all of a sudden stop reading. They flat line at 830-850 and then will randomly drop for a brief second. The STFT will all of a sudden drop to -18 / -20%. The wideband will creep down to 11.2.
Attached is a log from this morning. The first 30mins the 02's are swinging fine and the car is running great.
Around the 35min mark I rolled into the throttle to catch up to traffic and that is when things started acting up.
Around the 36min mark you can see the 02's flat line and the STFT dive down to -18 / -20%.
The car & mods:
2010 ZR1
LT headers (wrapped to help keep heat to the 02's)
No CATS
2.60 upper pulley
102 TB
I made no changes to the tune for MONTHS and went back and looked at previous logs. The 02's were swinging fine and the STFT stayed right at +/-2%. Went under to make sure no wires were rubbed through or burnt. No exhaust leaks and have been searching the forum for the past two weeks looking for any similar experiences.
Are the 02's just dead? Or am I missing something?
Log & Tune
9-14-20-1.hpl
10 ZR1_bolt-ons.hpt
So I got home and logged the car. WB reading 14.3-15.1 when steady driving, 02 sensors swing between 95mv-873mv. STFT are right around +/-2% when I am driving.
Now here's the weird part... If I drive the car for more than 20 mins they all of a sudden stop reading. They flat line at 830-850 and then will randomly drop for a brief second. The STFT will all of a sudden drop to -18 / -20%. The wideband will creep down to 11.2.
Attached is a log from this morning. The first 30mins the 02's are swinging fine and the car is running great.
Around the 35min mark I rolled into the throttle to catch up to traffic and that is when things started acting up.
Around the 36min mark you can see the 02's flat line and the STFT dive down to -18 / -20%.
The car & mods:
2010 ZR1
LT headers (wrapped to help keep heat to the 02's)
No CATS
2.60 upper pulley
102 TB
I made no changes to the tune for MONTHS and went back and looked at previous logs. The 02's were swinging fine and the STFT stayed right at +/-2%. Went under to make sure no wires were rubbed through or burnt. No exhaust leaks and have been searching the forum for the past two weeks looking for any similar experiences.
Are the 02's just dead? Or am I missing something?
Log & Tune
9-14-20-1.hpl
10 ZR1_bolt-ons.hpt
Last edited by C5kid; 09-20-2014 at 12:20 PM.
09-20-2014, 02:15 PM
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Update:
Took the car out again, cleaned the connectors on the 02 sensors. Looked great for the first 15mins then it started doing the same thing, trying to pull fuel, 02's get in a steady state of 830-850.
This time though it threw a CEL.
P0102 MAF Low frequency.
Cleaned the MAF with some CRC MAF cleaner. Still got the code.
Now wondering if the MAF is dying...
Took the car out again, cleaned the connectors on the 02 sensors. Looked great for the first 15mins then it started doing the same thing, trying to pull fuel, 02's get in a steady state of 830-850.
This time though it threw a CEL.
P0102 MAF Low frequency.
Cleaned the MAF with some CRC MAF cleaner. Still got the code.
Now wondering if the MAF is dying...
09-20-2014, 03:12 PM
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Update:
Negative... My Sky uses the exact same MAF. So I switched them. Car did the same thing.
Ran fine for 15mins then when rolling to a stop light, the 02s steadied out STFT tried pulling fuel.
Negative... My Sky uses the exact same MAF. So I switched them. Car did the same thing.
Ran fine for 15mins then when rolling to a stop light, the 02s steadied out STFT tried pulling fuel.
09-21-2014, 04:18 PM
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Solved:
Its the little things that bite ya.
So a buddy looked at the tune and said I def have a vacuum leak. The P0102 is a good sign of a vacuum leak somewhere.
Started going back in my mind what I did that would cause a leak or where it could be coming from.
Right before leaving LSFest, I checked my catch can to make sure it wasn't full or anything stupid.
When I screwed it on I must of not had it tight enough. Yep.. as soon as the car warmed up the can it would start to leak a little and that is when the tune would act all screwy.
Simple fix. I like those.
Its the little things that bite ya.
So a buddy looked at the tune and said I def have a vacuum leak. The P0102 is a good sign of a vacuum leak somewhere.
Started going back in my mind what I did that would cause a leak or where it could be coming from.
Right before leaving LSFest, I checked my catch can to make sure it wasn't full or anything stupid.
When I screwed it on I must of not had it tight enough. Yep.. as soon as the car warmed up the can it would start to leak a little and that is when the tune would act all screwy.
Simple fix. I like those.