2004 Chevy Avalanche MAF replacement

[John5]

Hi guys,

it's been a long time and haven't been doing any tuning for a while. Had to replace the MAF on my truck because I was getting P0101 and P102 and truck was definitely running bad. Got the replacement Delphi and truck runs and drives better and no more codes. The LTFT's are crazy now -12.5 on both banks after clearing and resetting them and driving for a while.

Should I adjust the MAF frequencies any or drive it longer to see if it improves? Also idle is very low and almost sounds like it will stall when coming to a stop and that happened 3 times but forgot to mention that earlier. Drove for just a couple miles and no codes came back so I hope the sensor itself is good.

Let me know
Thanks

[RDF1]

Whats the mods done to the truck?

Its possible the new MAF isnt exactly calibrated as your previous one or your oxygen sensors arent as good as they use to be.
Or it just needs some fine tuning.

[John5]

Whats the mods done to the truck?

Its possible the new MAF isnt exactly calibrated as your previous one or your oxygen sensors arent as good as they use to be.
Or it just needs some fine tuning.

I made some adjustments to the MAF and it has made a little improvement to the LTFT's. The low idle almost stalling has gone now. The truck has a cold air intake and a catback exhaust and it has been tuned for that for years now, just the MAF problem recently that has thrown things off I guess.

Thanks

[John5]

Hey guys,

took another drive today to monitor the LTFT's and something must definitely be wrong, either with a sensor or Hp tuners scanner. My LTFT for bank 2 went to -75.0 which I didn't know was even possible and bank 1 was reading -8.6. Any input and advice would be appreciated because I don't want to drive the truck anymore with those readings.

[twenglish1]

Post some of the data logs, ill take a look

[John5]

Hi and thanks, I have attached the log and tune on here.

[Alvin]

Let us diag it.. Post the log

[John5]

LTFTLOG.hpl Sorry, first log wasn't the correct one so here it is.

[Alvin]

This is a scanner bug/error. Try connecting to the vehicle and then go to "repoll for supported parameters" or something like that.

Restart the scanner too.

[John5]

Ok thanks Alvin, I'll try that later and see.

[John5]

Hi,

I've tried the suggested but the option isn't highlighted to actually work. I've also setup the afr error graph and can't get any numbers on the graph just cells visibly moving round without any numbers.

[twenglish1]

You have to be connected to the vehicle, key on, and not recording. If your chart is not plotting values it usually means a necessary channel is missing from the channel list or the chart is setup incorrectly.

[John5]

Hi twenglish1,

I?ve tried it both ways scanning and not scanning. Also the graph is set to AFR error, %, 2 decimals, cell hits 10, 25 for high -25 for low and mass air flow frequency for column axis labels copied and pasted. Channel list has both of them in there as well. Let me know if I?m missing something, it?s been a while. Thanks