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Turned out to be a bad coil in one of the cylinders. It was kinda weird that it didn’t have any misfire codes until I got an obd scanner to look at live data.
Turned out to be a bad coil in one of the cylinders. It was kinda weird that it didn’t have any misfire codes until I got an obd scanner to look at live data.
The ECU reset was just a test to determine if doing a reset did anything.
I would put your original O2 sensor (or a new NTK/Denso direct fit) one back in regardless.
The Bosch sensor is prone to cause its own issues which will compound and make it increasingly difficult to diagnose.
We're totally jacking this thread...but OP is gone anyway. What are your symptoms again? And what circumstances led to them? Can you lay out the issues and attempted fixes in chronological order?
symptoms did return. I’m getting erratic “dead spots” throughout the rpm range. Feels like intermittent misfiring or bad fueling.
it was happing at or in VTEC initially. My first fix was to swap my cat for a test pipe that I had. Seemed ok at first, then came back. Dropped it at my mechanic, asked him to adjust the valves. Exhaust was very tight, he said, and the issue seemed to improve. I drove 3hrs mixed highway and backroads to Moultrie GA, ambient temp dropped one morning, and I was having some rough idle, low rpm stumble, stutter. Throughout the weekend auto crossing, issue rarely happed on course. Drove home, no issues. Then the following week, started up again, maybe a little worse. Then, disconnected the negative term, let it sit over hr. And it seemed to fix the issue, car was pulling hard all the way to redline. Then came back.
a failing coil seems plausible, just surprised I’m not getting any codes/cel.
Turned out to be a bad coil in one of the cylinders. It was kinda weird that it didn’t have any misfire codes until I got an obd scanner to look at live data.
What did you see in the live data that clued you in to the coil?
symptoms did return. I’m getting erratic “dead spots” throughout the rpm range. Feels like intermittent misfiring or bad fueling.
it was happing at or in VTEC initially. My first fix was to swap my cat for a test pipe that I had. Seemed ok at first, then came back. Dropped it at my mechanic, asked him to adjust the valves. Exhaust was very tight, he said, and the issue seemed to improve. I drove 3hrs mixed highway and backroads to Moultrie GA, ambient temp dropped one morning, and I was having some rough idle, low rpm stumble, stutter. Throughout the weekend auto crossing, issue rarely happed on course. Drove home, no issues. Then the following week, started up again, maybe a little worse. Then, disconnected the negative term, let it sit over hr. And it seemed to fix the issue, car was pulling hard all the way to redline. Then came back.
a failing coil seems plausible, just surprised I’m not getting any codes/cel.
No mods or incidents that may have lead up to any of this, correct?
And yes, a failing coil was also what I was thinking. I wasn't sure if you had already tried changing them.
Check your plugs while you're at it.
These cars are incredibly picky on coilpack/sparkplug choices. If you're not ordering from a Honda dealer, make sure you're at least buying Denso/NTK.
What is strange about your issue is that there is no CEL and an ECU reset seems to temporarily fix the issue. But...the rest of it points at a weak coil.
No mods or incidents that may have lead up to any of this, correct?
And yes, a failing coil was also what I was thinking. I wasn't sure if you had already tried changing them.
Check your plugs while you're at it.
These cars are incredibly picky on coilpack/sparkplug choices. If you're not ordering from a Honda dealer, make sure you're at least buying Denso/NTK.
What is strange about your issue is that there is no CEL and an ECU reset seems to temporarily fix the issue. But...the rest of it points at a weak coil.
just left my mechanic, I’m going to leave the car with him on Monday to see what they can diagnose. I’m thinking I might be having more than one issue.
there is a noticeable problem right at VTEC engagement 6k. So there could be a problem there.
i also get intermittent low rpm power lose.
he also thinks it’s odd that I’m not getting any codes
just left my mechanic, I’m going to leave the car with him on Monday to see what they can diagnose. I’m thinking I might be having more than one issue.
there is a noticeable problem right at VTEC engagement 6k. So there could be a problem there.
i also get intermittent low rpm power lose.
he also thinks it’s odd that I’m not getting any codes
Car started running really rough and eventually died on the road. Good news was I was 100yrds from the shop. And I got a code! P1129 which I looked up as MAP HIGHER than expected
Engine just felt like I was running out of fuel before it died. I still have 4 bars of fuel left.
im just going to leave it here until we can get it fixed.
