Wolftrk99

iTrader: (5)

Stay with OE MAF aftermarkets arent worth the money youre payin for em!!! Way too many incosistancies with them...

2xLS1

iTrader: (25)

This. I regularly see virtual FF GM NNBS trucks commanding 11-12:1 A/F ratios in closed loop with whacked fuel trims running no ethanol 100% gas. Many times the ECM thinking there is up to 35-40% ethanol in the fuel when there isn't any. I've been asking HP Tuners to add a ethanol content reset to their scanner for a while now.

Wolftrk99

iTrader: (5)

Theres definitely a trend toward skewed ethanol content sensor data, but barring that being the issue it is very possible his MAF could be causing it too, especially now that he said he cleaned it and then it started throwing the codes...., granted none of us are doing much accurately here without data to go off of, not tryin to one up anyone or be an @$$ but point is without seeing data we are really just kinda drawing straws... And hypothesising!!!

1FastBrick

iTrader: (17)

I rarely use the ones supplied with tuning suites.

I have OEM and Snap On.

I hear Autoenginuity is pretty comparable in terms of OEM capabilities.

With the old MAF, the ethanol content would creep up into the 40% range and then I would get the system rich code's. But without real Diagnostic equipment to read the data, It's a shot in the dark.


As mentioned the aftermarket Mafs are basically junk and not worth the hassle. The money would be better spent on a tuning suite so you can work with a tuner, or learn to tune on your own. Or you try something like the AUto cal from EFI Live that allows you to go through a tuner and load a few different tunes from tuner. It also allows you to datalog. It just doesn't allow you to make changes to the tune.

Cowboy Tom

Well now with the MAF unplugged I should be able to see if it's the MAF or if I need the ethanol content reset? Correct? So far no codes since i've unplugged it, so I'm thinking it's MAF, and also I made the comment about an aftermarket MAF cause I wanted to get y'all's opinion? I've been debating OEM or aftermarket MAF
And also btw I've never ran over E10, I've always ran mid-grade or premium

1FastBrick

iTrader: (17)

Most likely you will get a MAF code now that it's unplugged.

The Ethanol content has to be reset with a Bidirectional capable Scan tool

Wolftrk99

iTrader: (5)

Unplugging maf and throwing code it shouldnt go into closed loop either, which means it will basically run in open loop until it sees a valid MAF signal, baro signal and iat signal.... Which are all part of the MAF sensor.... Which should make ecm ignore o2 signals..... If im wrong please correct me....

1fastBrick, what suite would you recommend? Want to get more familiar with ecm operations and tuning and have a fairly decent comprehension of it but would like to learn something new. Was thinking about hptuners vcm, but want an opinion from someone more familiar...

2xLS1

iTrader: (25)

It will run in closed loop with no MAF. Will be running in speed density mode though. If you cn use a scanner that displays commanded A/F while in closed loop, that will tell you if it need the alcohol content reset. Should be somewhere between 14.7 and 14.1 if using E0-E10.

People that use EFI Live seem to like it. People that use HP Tuners seem to like it. I've used both and prefer HP Tuners, but I use it way more. The Chinese Tech 2s are getting so cheap now it might just be time for me to get one.

Cowboy Tom

Yea with the MAF unplugged it forces the ECM to relay on the O2 sensors, ECT and also TPS, so it will still go into closed loop, and so far, since I've unplugged it, it has a code for MAF and IAT (of course) but still no P0172 or P0175, so I think its my MAF, so its still reading a signal, but its just incorrect so it telling the ECM false info causing it to run rich, Correct?
so i think I'm gonna go ahead a plug the MAF back up for now and order a new one
Thanks for the help

2xLS1

iTrader: (25)

Yep, nothing like replacing expensive parts without a real diagnosis.