I got some data with MAF on it. It looks like it's working.
https://www.youtube.com/watch?v=6hg1PfST5GM&feature=youtu.be

If all the sensors look ok. Then I'm not sure what to replace.... Back to the fuel regulator?

Does your idle ever get to 700rpms, +-50 when the engine is fully warmed up?

If I remember correctly my MAF reading is closer to 4 g/s at idle when warmed up but I will try and double check tomorrow.

When the LTFT goes below 20 is the MAF still the same or does it change also?

Do you have any exhaust leaks?


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The more I think about your MAF readings I am going to say that your MAF, despite the cleaning, may be bad due to being out of calibration. The MAF, at least of this age, is like the throttle body where the values should be linear in nature as the RPMs increase.

I’ve been trying to find the PID for the MAF for my ScanGauge. It’s annoying I have to plug in my Innova scanner or use my app to see it.


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I have to use my Launch.

It has been years since i looked at my MAF data but usually at idle the MAF reads close to or spot on the volume of the engine, or at least for me until one gets to anything under three liters.

I am thinking though the OP’s MAF has over time lost its ability to calibrate.

His LTFT was all over the place and it should be steady at idle. I think he’s definitely got a sensor giving bad info to the ECU and the O2 sensor sees the wrong fuel map and corrects the trims.


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So give or take my MAF reading at idle, fully warmed up reads about 4 grams per second. If the OP’s MAF is reading double that, then either that reading is based upon a bad MAF or the MAF is producing those numbers due to a normal than higher idle (which shouldn’t be the case).

If it was my rig I would clean the IAC and the TB well, then see if the values change at all. If the MAF value is still high, I would replace the MAF with a new one. I believe Denso makes one......

If he has the old turbine style MAF they cost $600 new. Junk yard units from 4Runners or V6 Camry's of similar years are interchangeable, I had a Camry MAF on mine for years.

It seams to idle around 1000 RPM wich is high.

I don't think I have an exhaust leak. But I don't see the LTFT go over 20.

I have an Innova scanner but couldn't figure out how to see live data in the app.


It does seem to idle a bit high. What is the IAC? I did a light cleaning on the TB. But I could take it off and give it a good cleaning. I'm also wondering about the throttle position sensor. At idle shouldn't it read zero and not 10%?

I am lucky and have a 99 I thnk a Denso is only $100.

Ok, the IAC (idle air controller) is located under the throttle body. It is attached with four soft brass screws. There is a gasket that goes between the IAC and the throttle body so you may need a new one before reinstalling. Make sure to dutifully take note of how the coolant and vacuum lines attach. Use the search engine to find out a better write up on such.

IMHO, if you had new 02 sensors your fuel trims would probably register quicker and more accurate than at the moment but don’t think it is your problem.

Nope, the TPS seems to be reading correctly. With the butterfly closed the sensor should read about 9. That is why the value of 8 for your MAF at idle is something to make note of.

Good luck.....👍🏻

I just dealt with a bad TPS. It wouldn't register the idle throttle position correctly and would cause it to stall. Also upon deceleration, the engine speed wouldn't decrease until a few seconds after I let off the gas (sort of like a runaway vehicle). If you don't have symptoms like these then assume the TPS is good.

You're on the right track though. The major sensors that control fuel are MAF, O2 sensors and TPS.

So I'm going to see if I can find an IAC seal local on Saturday and clean it out. I watched the Timmy Tool man's video on cleaning it and sounds like my issue. I also need to stop my pick n pull and might just grab a throttle body.

It’s worth getting one or two spares out of the yard just for the spare factory sensors.


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Well that's gross...

My local dealer ship didn't have the gasket in stock so I got to wail tell Tuesday to put it all back together.
I also found a pretty bad oil leak...