MAF reading 3.4g on my 2.7

Does anyone know why on earth my MAF is reading 3.4g at idle? As far as I know they should match the engine displacement. Can anyone verify this? Thanks!

 

What year?

 

Check his profile, says 99.

Although I'm not sure what a pre runner 4x4 is. Conversion?

 

Yeah, it’s a 99 2.7 PreRunner. I have been chasing drive ability issues for years. High +10 ltft. If I am correct and this should read 2.7 grams per second either I have the improper maf (from a 3.4) or the ecu is incorrect for the truck. If the ecu thinks it’s getting 3.4 g of air seems to me it would certainly be trying to add fuel. The maf that’s in there supposedly came from a 2.7, bought it from a boneyard online. Any techies know for sure?

 

I'd start by changing that sock you've been using for a gas cap and the burned out CEL lightbulb.
That S2 O2 diode under passenger seat isn't helping driveability either.
Clean the MAF with a stiff wire brush and Drano liquid if you're feeling adventureous.

 

Replace upstream o2 with new Denso unit of the correct variety. 99 should be

$53 234-4161 Oxygen Sensor with 15.35” 4-Wire Harness

234-4161 or

$52 234-4162 Oxygen Sensor with 4-Wire 10.5” Harness for Non-California, Non-4WD Lexus/Toyota

234-4162, and inspect your intake boot for cracks creating vacuum leaks. Have you injectors cleaned- mabye they a bit clogged, forcing ECU to "add fuel" to compensate. +10 aint terrible though. That's the beauty of fuel injection.

 

I understand your thinking... Spitballing and thinking out loud here, if there was a slight vacuum leak the O2 sensor would compensate but the g/sec would be lower... is the idle normalish, not over 800 rpm? The 4 cylinders seemed to be different throughout the years... some have a MAP sensor some dont. The brake vacuum booster is often overlooked for vacuum leaks... squeeze the hose and look at STFT for an improvement. Raise the rpms slowly and hold at say 2k and look at STFT... if it improves toward 0 then there is definitly false air somewhere. What does the IAT show... this is built into the MAF as far as I know. PCV valve OK?

 

Can you guys re-read the original post? I know my O2 is correct. I’d like to know how many grams per second is a 2.7 supposed to read at idle. I’m fairly sure it should be 2.7. This is where I’d like to concentrate. My scanner is reading 3.4. Lol. If it’s a nice day where you live, have a 99, a 2.7, scanner and a couple minutes to help me out please see what your maf is reading. I will send you a Dunkin’ card. Thanks

 

Mine doesn’t whistle when going down the road , or did you put some FlexTape over the hole already... lol, smaht ass

 

It's on my to do list for the wet carpet fix Rubber floormat on passenger side delete mod for now keeps it dry till I can find a screwdriver
I just turn up the radio for Taco whistle drown out mod

 

Do you think the whistle and drip are related? Would be nice to fix both with flex tape once I find a screwdriver.

 

Make it a case of BJs and I'll bring full diagnostics immediately
Can't eat donuts got Sugarbeadies. Sickashellnemia and HPV2

 

I read mine in cfm..I think. I don't think it's going to match the liter of the engine.

 

Mine read somewhere from 3.3-3.6 at idle. It's fine

 

Bummer. Thanks

 

I am curious how a mass and weight label is used to measure volume Looking to learn something new !!

 

the "perfect" ratio of air to fuel is apx 14.7 to 1. So many grams of air per second equals so much weight then the PCM calculates fuel based on that, modified by air temp, throttle position etc.etc.