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I am see misfires on both banks, mainly on cylinder 2 and 7. the car is hesitating under load with a ruff idle popping . i am pretty new to hptuners and don't really know what to make of the data i am seeing. Are there any other channels i should be looking at in hptuners?
i noticed the iat seems high to me but i was idling when i saved that.
i am not sure what LT B1 is? its showing red
what I've tried so far:
swopped plug wires on cylinder 2 and 7
swopped the number 7 coil with number 5 coil.
I am working on my 02 camaro ls1 v8. The car is mostly stock except for a few bolt-on's below. Is bank 1 the passenger side? could that an O2 senor causing that?
k&n air intake
96 mm throttle body
texas speed LT headers
texas speed cated y pipe
MSD wired
Is P0300 the only code you’re getting? I recall Bank 1 is the driver side bank. I would look for signs of exhaust leaks (black soot) on the head and were the headers connect to the y-pipe to confirm that fresh air isn’t making it’s way into the exhaust that makes your car think that it’s running lean which makes it add fuel. Inspect the 02 sensor. Unplug the harness and look for signs of damage or water intrusion. Make sure the plug wires haven’t been damaged. The sensor may ultimately be bad and just needs replacing. For the misfires, inspect the plug wires and boots for signs of melting. Unplug the wires and re-intstall to make sure they’re seated on the plug. If the plugs are old, you may want to change all 8.
Yes that’s the only code I got. I changed the drivers o2 but no change. ill have to jack the car up next time I get the chance and inspect the y pipe for leaks.
First off pull all plugs and inspect. Keep up with which cylinder they come from. U need to check injectors. U can manually test them while idling with scanner. U can also disable closed loop which is O2 sensors for a test of O2s. Last why is water temp a lil hot? Could be a possible bad head gasket issue.
Also if this comes down to basic diag stuff. Check fuel pressure. Pull plugs. Check each coils spark. Test injectors noid light kit. Compression test each cylinder.
I wouldn't worry about the ltft until the misfires are fixed. A cylinder not firing will put unburnt oxygen in the exhaust so the sensor will read it as lean and add fuel until it gets not lean. Misfire is what you are chasing first and the ltft may come back in line. check the plugs, see if #7 is wet. if the plug is wet with gas then its either not firing or there's not enough compression to let it light off. Since you swapped the coils and wires that rules them out. so its either the spark plug, injector, or a compression issue. you could unplug the o2s while your testing so they wont be adding fuel unnecessarily, or turn the o2s off in the tune
Update: as of this afternoon, the misfires moved to cylinder 1 and 3, There are much more misfires now then the file i shared earlier in this thread. Now getting p0300 and pending p0303. I don't understand why the misfire moved especially when i did not do anything with number 3 yet. i dont have a log file to post this time.
What spark plugs are you running? Are you still seeing misfires on #7? I can only speculate that you’ve been running rich long enough on bank 1 to start fouling your odd cylinder number plugs. I’d check out your driver’s side plugs.
i was NOT seeing any misfires on 2 and 7 last night, only 1 and 3. this time i noticed 12000 misfires on 3 and 5000 on 1.
i swopped the o2 sensor on bank 1 Sunday and cleared the codes. Monday morning i drove in to work it with running okay not really misfiring to much and on the way home it was misfiring really bad.
Update: as of this afternoon, the misfires moved to cylinder 1 and 3, There are much more misfires now then the file i shared earlier in this thread. Now getting p0300 and pending p0303. I don't understand why the misfire moved especially when i did not do anything with number 3 yet. i dont have a log file to post this time.
When that happened to me, the culprit was the little wiring harnesses that sit between the coil packs and the rest of the engine harness.
I replace them with OEM and the misfires went away. I think the issue was probably just the connectors, but I didn't troubleshoot further.
I had replaced the stock motor in my C5, and one night it hit me that that the harnesses were the only thing that I hadn't ruled out yet. Everything else was either proven good before the motor swap or ruled out from testing or replacing. I don't recall which harnesses I used at first, but they were from an aftermarket vendor.
For some reason I thought I needed an aftermarket harness to use gen4 coils in a gen3 car, but the ones I'm using now are OEM, part number 12621253.
Newer coils because Holley valve covers... Had 'em painted the same color as the car. This is the old/flaky wiring:
When that happened to me, the culprit was the little wiring harnesses that sit between the coil packs and the rest of the engine harness.
I replace them with OEM and the misfires went away. I think the issue was probably just the connectors, but I didn't troubleshoot further.
That's a good point. I have people say all the time well if its the wiring it will set a circuit dtc. Which if you unplug a coil it will set a circuit fault dtc. But it checks 1 circuit per coil, if that circuit is OK there's no fault seen so no dtc. But the power or ground to the coil the pcm has no way of knowing, it just knows that cylinder isn't contributing.
Sorry I know that is kinda out in left field. It is odd for it to move cylinders like that, makes it look even more like a wiring issue. Have you checked the grounds on the heads?
i was chasing misfires on cylinder 3 with no luck. On Monday i drove it to work after changing the spark plug on 3 for s/g's because i already had the plugs. it drove fine in the morning and was 75 degree's out. On the way home it was 89 degree's outside and the car started misfiring again. i realized i didn't notice the radiator fans on come. So yesterday i hooked up hptuners and turned on the fans with HPtuners just to make sure they worked, which they did. i noticed the coolant got up to 223 idling in the driveway so i turned the fans on with hptuners again and noticed the temp come down. So i am not sure if the fans are being told to turn on but they work. coolant temp sensor?
also noticing:
IAT is still high
LTB1 is high
misfires moved to cylinder's 2 and 7
injector flow rate low? 31 lb/h and i think it should be 36lb/h. would that cause misfire?
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chasing P0300 have log files 
