Sputtering / Misfiring in Neutral under load

[Misho]

Hi All,

I've been tackling an issue with my 2000 3.4L Auto 4runner for a while now.

When in neutral, if I go wide open throttle, or anything above 1/2 of throttle, the car sputters, misfires, and slowly revs up to the redline. If I slowly and progressively press the throttle, it doesn't misfire, and can get to the redline.

When in Drive, the car runs fine, until I go about 1/2 throttle or more, then you can feel the car really struggle.
The odd thing is that sometimes this issue *somewhat* disappears, and other times it's really bad (misfires so bad that I cannot go above 45mph), and the more throttle, the more it misfires.

Anybody experienced similar issues?

The car idles fine and starts fine

I've replaced Plugs, Coilpacks, plug wires,with OEM parts and it made no difference
Car has been daily driven like this. It's not bad gas either.

Looking for any suggestions on how to troubleshoot & next steps?

Thanks!

Edit: Forgot to add the CELs; *derp*

Mass air sensor
Mass air sensor intake temp
Random misfire

Any other suggestions before I go and buy a MAF? Could I confirm that it's bad by unplugging it? I have an OBD2 reader, and it was reading different grams/second values, and it seemed that it was working.

 

[octanejunkie]

No codes?

 

[Misho]

No codes?

Ah, I am such an idiot. I don't remember the code numbers, but I remember their descriptions. There were three codes:

Mass air sensor
Mass air sensor intake temp
Random misfire

 

[octanejunkie]

I would start with cleaning your MAF sensor

Research how to do that properly and you might just see those codes disappear and performance return

 

[Misho]

I would start with cleaning your MAF sensor

Research how to do that properly and you might just see those codes disappear and performance return

Will do ASAP, most likely today. I'll let you know the results.

Thanks

 

[Misho]

Well that was a quick solution! I took the MAF sensor, thoroughly cleaned it with sensor cleaner, and NO MORE issues!
Car runs like brand new. Better than 8 years ago when I bought it!
My faith in the T4R is restored lol. Now onto the death sway issue (either panhard bar bushings or rear LCA bushings)

I've cleared all codes. I'll post back later in the week and see if any codes return

Thanks for the help.