Pending Codes P0101 P0341 Issues
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On The Tree
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Pending Codes P0101 P0341 Issues Forged LS3 with a small cam
locally dyno tuned then street tuned as I had high negative LTFT and hated the trans shifting.
Eng light doesn’t come on but I will get a pending 101 MAF code and it’ll pop thru the intake under throttle. Random 341 code as well even with new cam sensor. MAF was new with the build and 1k miles on the build.
Could it be an intake or header leak causing this? Tune related? 02’s?
As soon as I clear the pending code it runs normal. Usually after WOT it runs bad. Everything with the engine is new but stock coils.
locally dyno tuned then street tuned as I had high negative LTFT and hated the trans shifting.
Eng light doesn’t come on but I will get a pending 101 MAF code and it’ll pop thru the intake under throttle. Random 341 code as well even with new cam sensor. MAF was new with the build and 1k miles on the build.
Could it be an intake or header leak causing this? Tune related? 02’s?
As soon as I clear the pending code it runs normal. Usually after WOT it runs bad. Everything with the engine is new but stock coils.
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On The Tree
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Just unplugged the MAF. No change to idle. It idles between 600-750. Did pull up codes 102 & 113 and Cam sensor code is still coming up. Maybe thr MAF is bad? No check engine light which is weird. Just pending codes on thr scanner. Wonder if a bad crank sensor would cause the cam sensor code?
I was dumping fuel at one point with 2 open injectors. Wonder if the speed engineering CAT is now shot.
I was dumping fuel at one point with 2 open injectors. Wonder if the speed engineering CAT is now shot.
Last edited by Carp; Mar 14, 2025 at 05:31 PM.
I'd take it back to your tuner get them to hook up all the equipment and make a pull or two they should be able to figure out in short order where the problem is. Pop thru the intake is usually lean or valve float
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It took me two months to get in touch with him to correct it having -20 LTFT and fix the trans tune that’s still off. It’s been popping since the original tune. It use to be after a wot run it would backfire as soon as I gave it gas but he corrected the LTFT some. I’m looking to install the turbo kit this weekend and then have someone else retune it.
truck runs fine until the 101 code starts pending. As soon as I clear it then it runs normal again. Maybe the new MAF is bad or a bad wire. I was thinking the cat is clogged due to the 2 injectors dumping fuel that I fixed with a new ECM due to an arc while checking spark fried the ECM in those two spots. I had them copy my ECM to a new one. Starting to think it’s in the tune. All sensors aside from the crank are new.
cam is 216/228 .600 with btr dual valve springs. Engine only has 1k miles.
truck runs fine until the 101 code starts pending. As soon as I clear it then it runs normal again. Maybe the new MAF is bad or a bad wire. I was thinking the cat is clogged due to the 2 injectors dumping fuel that I fixed with a new ECM due to an arc while checking spark fried the ECM in those two spots. I had them copy my ECM to a new one. Starting to think it’s in the tune. All sensors aside from the crank are new.
cam is 216/228 .600 with btr dual valve springs. Engine only has 1k miles.
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Between "high negative LTFT" and P0101, I'm guessing you've either got a vacuum leak or a bad MAF sensor. First thing I'd look for is any way that air could be leaking in the intake manifold at idle. If you have a PCV hose running from the intake manifold to the valley cover, make sure both valve covers are capped.
Bad grounds can also cause weird codes - if the MAF and cam sensors are grounded together that would be a suspicious coincidence.
Bad grounds can also cause weird codes - if the MAF and cam sensors are grounded together that would be a suspicious coincidence.
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It goes crazy lean when it happens. STFT will be 25-30 while LTFT stay at -14. I’m debating on a clogged cat. I’m also going to trace the ground back for both the MAF and Cam sensors. The MAF is new and the engine only has 1,000 miles on it now. I have 2 catch cans and I’m worried if they are leaking somehow. I’m going to verify but last check they were fine.
Engine runs good aside from idle from 650-750. After I hit 4k when it goes straight to MAF and no MaP (SD) is when it trips a code. If I stay under 3k it appears to be fine for the most part. Once it throws the code it backfires horribly and won’t accelerate.
Im getting ready to go turbo and SD tuned but would like to get this worked out prior to.
Engine runs good aside from idle from 650-750. After I hit 4k when it goes straight to MAF and no MaP (SD) is when it trips a code. If I stay under 3k it appears to be fine for the most part. Once it throws the code it backfires horribly and won’t accelerate.
Im getting ready to go turbo and SD tuned but would like to get this worked out prior to.
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Teching In
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Fwiw it sounds similar to my lm7 swap with no kitties. I don't recall the exact codes but MAF codes nonetheless. Not saying your issue isn't clogged cats but just saying mine exhibits similar behavior without them.
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Forget what I said about a vacuum leak - if that was the issue then it would be lean at idle and get better at higher RPM / more load.
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I pressurized the exhaust system and found that both headers are leaking at the heads so I’m pulling them off to replace the gaskets. I hate the noise they make so I’m going to wrap them while I have them off.
I’m also going to an LS7 MAF and 4” housing. The MAF housing now is 1/8 too small for the filter connection. I’ll get it retuned and that will hopefully fix the MAF issue. Just not sure on the CAM sensor.
I’m also going to an LS7 MAF and 4” housing. The MAF housing now is 1/8 too small for the filter connection. I’ll get it retuned and that will hopefully fix the MAF issue. Just not sure on the CAM sensor.