4R Error codes

Aquabear

New member
Error codes show up as they want

Went into Advanced Auto Parts, used Scan code reader and we got this....

2016 4Runner Trail 52,000 mi error codes....

Po172
Po175
O2 Sensors
Bank 1 $179
Bank 2 $75

O2 Sensor

In pic not showed is Green "Off Road" light is flashing, i just suck at takin this pic

Last time these dashboard lights showed Dealer gave me a new ECU, yet here I am again.....

Thoughts???

Could there be a loose ground somewhere?

I had someone install new speakers and a amp/sub combo, a little while after is when it all started (about 2 months and a few thousand miles after) BUT radio and amp and speaklers all work fine with no issues at all.

Using Mechanical Breakdown Insurance I can go anywhere now BIG question let Delaership who cant seem to diagnose this when it comes up OR let a local and trusted non-dealership Service shop handle this?
She drives but traveling to Florida so I need her at 100%.
 
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This would be covered under your powertrain warranty...if a dealership can't diagnose an 172 and 175 issue they should NOT be in business !!...if you have a decent scan tool O2 sensors are fairly easy to diagnose if it is that... 0172 and 0175 are RICH codes for bank 1 and 2...could be coolant temp sensor, leaking pressure regulator, MAF sensor, bad fuel injector...you just need to do a little troubleshooting so you don’t burn up your cat !!...let us know what the stealership finds !!

P.s. watch this YouTube video...Paul Danner is the “Jedi Master” of auto diagnostics !!

https://youtu.be/ClCuoi3JxEI
 
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I would take it in ASAP. Running rich constantly can impact the lifetime of the motor via cylinder whashdown. Most likely the MAF sensor, but impossible to diagnose without being hands on with it.

Like stated... should be under warranty.
 
I would take it in ASAP. Running rich constantly can impact the lifetime of the motor via cylinder whashdown. Most likely the MAF sensor, but impossible to diagnose without being hands on with it.

Like stated... should be under warranty.

Agree on the MAF sensor, but also interesting in the parts list, the OP put the URD MAF calibrator....... Might be a starting point there....
 
Agree on the MAF sensor, but also interesting in the parts list, the OP put the URD MAF calibrator....... Might be a starting point there....

Oh WOW.... Yea I would take that off ASAP as that could void the warranty for the 02s and other things. Plus.. it could be the root of the problem.
 
Agree on the MAF sensor, but also interesting in the parts list, the OP put the URD MAF calibrator....... Might be a starting point there....

This started before doing any mods.

Except for new speakers and addition of Amp/speaker combo installed under passenger front seat....??
 
Oh WOW.... Yea I would take that off ASAP as that could void the warranty for the 02s and other things. Plus.. it could be the root of the problem.

Nope. It happened before any mods were installed.

Thou new speakers were installed AND added an AMP/Speaker combo under front pass seat.....???
 
Nope. It happened before any mods were installed.

Thou new speakers were installed AND added an AMP/Speaker combo under front pass seat.....???

Whatever the case... If you expect to have it fixed under warranty. You better remove the MAF translator. The cause is most likely the MAF and anyone with the most basic troubleshooting skills is going to immediately suspect the aftermarket device that is translating the signal to the ECU.

And just a general rule of thumb for me based on many years of modifying cars/trucks... I don't make any changes or install any additional parts when I have an ongoing issue to resolve. It just complicates the equation. One issue at a time.. one change at a time really simplifies things.
 
Removed the MAF calibrator, reset system and after two weeks error code came up again......

I am going to go with the last change made to the engine before this happened and that was changing the speakers(which I highly doubt) and removing the Amp/Sub under the front seat. I am going to fully check all wiring for power and ground as I think they may be loose and causing this error.
 
I would agree with the above, remove the MAF recalibrator(check) and go to a dealer to have issue documented/resolved.
FWIW, I had similar issue(02 sensor code) from two different vehicles 4 or 5 times over a 5 plus year period. Long story short, bad gas. I always refueled at the same local Mom&Pop store. They seemed to have an issue with their pump maintenance/tanks/supplier or something. If applicable you might try a fuel system cleaner and using a gas station that stays busy. I've not had any fuel related issues in several years.​
 
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