0x10: P0101 - Mass or Volume Air Flow A Circuit Range/Performance (Pending)

[fin]

Hi,
need help whit my tune not running smoothly popping up code P0101 I even change the MAF sensor.
Tune was done by a local tuner
04 GMC Savana van lq4 6.0 CNC heads cam (LUN-20540710
Camshaft, Hydraulic Roller Tappet, Advertised Duration 262/268, Lift .531/.531,)

[5FDP]

So it happened after the tune or after you ripped the engine apart to install the camshaft/heads?

That is a circuit code so I'd be looking at the wiring.

Something else seems screwy with that log. Commanded AFR goes way lean under heavy throttle but that is the opposite of what the computer is asking. You are also going to run into problems with a cat test because you removed the rear o2 sensors. If you still have them just plug them back in so the circuits are not left open. Leaving them open will cause lean/rich swings as it tries to do the test, you can see the commanded AFR jump to 16-17 in closed loop. COT needs to be disabled for this as well because the rear o2's are disabled and likely not there.

Add knock retard and your injector pulse width avg to your logs, that's good stuff to be watching. I wouldn't be surprised if the tuner did this thing knowing you had too small of fuel injectors. Not trying to rain on your parade but that is just the truth.

[cobaltssoverbooster]

move the harness around and see if you can get the code to switch to a hard fault instead of a pending fault. sometimes the connectors loose tension and a quick pin push, re-tension, re-insert process can resolve an intermittent connection issue.

[fin]

So it happened after the tune or after you ripped the engine apart to install the camshaft/heads?

That is a circuit code so I'd be looking at the wiring.

Something else seems screwy with that log. Commanded AFR goes way lean under heavy throttle but that is the opposite of what the computer is asking. You are also going to run into problems with a cat test because you removed the rear o2 sensors. If you still have them just plug them back in so the circuits are not left open. Leaving them open will cause lean/rich swings as it tries to do the test, you can see the commanded AFR jump to 16-17 in closed loop. COT needs to be disabled for this as well because the rear o2's are disabled and likely not there.

Add knock retard and your injector pulse width avg to your logs, that's good stuff to be watching. I wouldn't be surprised if the tuner did this thing knowing you had too small of fuel injectors. Not trying to rain on your parade but that is just the truth.

?The cats have been deleted so the first tuner turned off the rear o2?s. if the cats are gone and the sensors are still there should I just turn them back on? If I upgrade my injectors to the 8.1l 42lb injectors would this help you think?

[5FDP]

Leave the sensor DTC's set to disabled. You just want the sensors plugged in so the circuit is not left open.

I'd use the 31lb/hr 8.1 injectors before the 42 marine injectors because those are tougher to get injector data for.

I'd still be curious as to what a different log would look like. Add those extra channels and re-poll for supported parameters with the VCM scanner. Curious if the commanded EQ ratio channel goes back to normal or still reports those weird lean values under hard throttle.