Just finished my cam swap on my 08 Escalade. Not sure if it?s something in the tune that?s causing the misfires or something physical on the truck. I had to replace the OBD2 fuse to write the current file but starts up just doesn?t sound like it?s on all 8 and there?s no change in tone disabling that injector bank with the scanner
Originally Posted by Camiking23
B1S1 O2 is shorted to ground (less than 10mV the whole log), and closed loop is dumping as much fuel as it can trying to bring that B1 O2 volts up.
That means there?s a bad ground somewhere or that 02 sensor specifically?
No, too much ground. Signal wire shorted to ground will pull the signal 'low' (high = voltage, low = ground).
Or, all the bank 1 cylinders are misfiring, which sends all of the air out the exhaust port in the same condition it went in. Oxygen that hasn't burned will be detected as 'lean', because O2s do not measure unburned fuel, they measure oxygen. The O2 signal is ~450mV at stoich, less than 450 if lean, and more than 450 if rich.
Since you just had the whole top of the engine apart I'd be figuring out exactly which cylinders are misfiring, then looking for what those cylinders have in common (like, all of one bank shares the same coil harness, all the wires go through a single connector...).
I?m thinking it might be the ground strap on the driver?s side or the coil ground for the driver?s side. All 4 driver side cylinders are missing and exhaust smells strongly of fuel I?ll take my meter out in the morning to check. Appreciate passing ideas around!
Both banks of coils share the same ground (G102), but they do have separate fuses (INJ A, INJ B).
Well i can say that it is the ground for the driver side coils. Adding a ground directly to the coil wiring did the trick but i have to dig into it more. This is a small cam but i still may get a remote tune i can adjust simple parameters but id like to be able to tune efficiently. How's the log look?
Last edited by Camiking23; 12-01-2024 at 08:12 PM.
They share the same ground point, but there's more than one wire there, more than one eyelet under the single bolt. G102 should be on the left front of the block up a little ways from the pan rail. Like behind the P/S pump.
Looks OK by the trims, but there may still be something going on with bank 1. Compare the shape of B1 (spiky) to B2 (smooth).
Attachment 154981
If the O2s are old or you don't know the last time they were replaced, I'd be changing them, if nothing else as a maintenance item.
Could the post cat O2 sensor being unplugged cause this fluctuation on the driver side? I'm planning on installing my AEM wideband and the O2 for it is there instead.
Found the Gen4 idle tuning guide here yesterday by BigMike42 and I've applied some of the idle changes but the truck idles good its just in park if i rev any it hangs i may have missed something.
Nothing from as early as 2008 used the post-cat sensors for fueling, they are for catalyst monitoring only. That changes somewhat around like 2014-up.
May I ask how the gen V's use the post-cat o2 sensors for fueling?!
Look into P2096 thru P2099. It exists in later-years Gen 4s, not just Gen 5.
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