MAF Readings (1 Viewer)

[sleepycruiser]

What is the normal MAF reading on a GX470? Mine is reading 4.87 g/sec.

I’ve got the P0171 and P0174 codes.
Cleaned the MAF and still getting the codes. Doesn’t appear to be an vacuum leaks as my idle and drive RPMs aren’t sporadic.

 

[Rednexus]

Generally 1 g/sec per liter of displacement at idle is normal, which you are very close to.

That being said a tiny vacuum leak can cause all sorts of issues and may not show up in a MAF reading at idle. To find one get a can of carb cleaner (or, if you want to be safer, a small propane torch that is open but not lit) and spray it on all of your vacuum connection, including areas such as the intake manifold gaskets, throttle body, etc. Watch your short-term fuel trims while spraying. If your short-term trims go rapidly negative when you apply the carb cleaner/propane near a certain area, you have found your vacuum leak.

Your MAF could also be going bad. If it's original I'd probably replace it with a new OEM Hitachi sensor (around $60 for the VVTI engines....not sure about the older ones), just to rule it out as a culprit.

 

[sleepycruiser]

Generally 1 g/sec per liter of displacement at idle is normal, which you are very close to.

That being said a tiny vacuum leak can cause all sorts of issues and may not show up in a MAF reading at idle. To find one get a can of carb cleaner (or, if you want to be safer, a small propane torch that is open but not lit) and spray it on all of your vacuum connection, including areas such as the intake manifold gaskets, throttle body, etc. Watch your short-term fuel trims while spraying. If your short-term trims go rapidly negative when you apply the carb cleaner/propane near a certain area, you have found your vacuum leak.

Your MAF could also be going bad. If it's original I'd probably replace it with a new OEM Hitachi sensor (around $60 for the VVTI engines....not sure about the older ones), just to rule it out as a culprit.

Thanks. That was my next question…so even if a MAF is reading within the correct tolerances it can still be bad?

I took the MAF out of my wife’s 2008 and put it in my 2006 (which is the one with the CEL) and been letting it idle for about 20 minutes and so far no CEL…so hoping the MAF is the issue.

 

[sleepycruiser]

CEL just came on with the other MAF in there.

 

[sleepycruiser]

Well, this probably wasn’t helping.